Emerson Vsm Users Manual 35391S Rev 08b Booklet.indb

Emerson Air Compressor 450XL 35391S_Rev_08b

0020ab6d-0f13-4264-953b-fba9d83b13ec Emerson Air Compressor VSR User Guide |

2015-01-05

: Emerson Emerson-Vsm-Users-Manual-165002 emerson-vsm-users-manual-165002 emerson pdf

Open the PDF directly: View PDF .
Page Count: 145

Download
Open PDF In Browser	View PDF

VSS/VSR/VSM single screw compressor
Operation and service manual

Important Message

READ CAREFULLY BEFORE INSTALLING AND STARTING YOUR COMPRESSOR.
The following instructions have been prepared to assist in installation, operation and removal of Vilter™ Single
Screw Compressors. Following these instructions will result in a long life of the compressor with satisfactory
operation.
The entire manual should be reviewed before attempting to install, operate, service or repair the compressor.
A compressor is a positive displacement machine. It is designed to compress gas. The compressor must
not be subjected to liquid carry over. Care must be exercised in properly designing and maintaining the
system to prevent conditions that could lead to liquid carry over. Vilter Manufacturing is not responsible
for the system or the controls needed to prevent liquid carry over and as such Vilter Manufacturing cannot warrant equipment damaged by improperly protected or operating systems.
Vilter screw compressor components are thoroughly inspected at the factory. However, damage can occur
in shipment. For this reason, the equipment should be thoroughly inspected upon arrival. Any damage
noted should be reported immediately to the Transportation Company. This way, an authorized agent
can examine the unit, determine the extent of damage and take necessary steps to rectify the claim with
no serious or costly delays. At the same time, the local Vilter representative or the home office should
be notified of any claim made.
All inquires should include the Vilter sales order number, compressor serial and model number. These can be
found on the compressor name plate on the compressor.
All requests for information, services or parts should be directed to:
Vilter Manufacturing LLC
Customer Service Department
P.O. Box 8904
5555 South Packard Ave
Cudahy, WI 53110-8904 USA
Telephone: 1-414-744-0111
Fax:1-414-744-3483
e-mail: info.vilter@emerson.com
Equipment Identification Numbers:
Vilter Order Number:
Vilter Order Number:
Vilter Order Number:
Vilter Order Number:

_______________________Compressor Serial Number: _________________
_______________________Compressor Serial Number: _________________
_______________________Compressor Serial Number: _________________
_______________________Compressor Serial Number: _________________

Table of Contents

Important Message ..............................................................................................................3
Standard VILTER Warranty Statement ..................................................................................6
Standard VILTER 5/15 Warranty Statement ..........................................................................7
Long Term Storage Requirements .........................................................................................8
Description.........................................................................................................................10
Foundation .........................................................................................................................12
Rigging and Lifting .............................................................................................................19
Installation .........................................................................................................................23
Slide Valve Actuator Installation & Calibration ...............................................................35
Slide Valve Operation ....................................................................................................38
Slide Valve Actuator Trouble Shooting Guide .................................................................39
Operation Section ..............................................................................................................43
Notice on using Non-Vilter Oils ......................................................................................43
Operation .....................................................................................................................44
Pre Start-Up Checklists ..................................................................................................52
Field Piping and Mechanical Requirements ....................................................................53
Field Wiring Requirements ............................................................................................54
Stop Check Valve Operation ..........................................................................................55
Service ..........................................................................................................................56
Maintenance .................................................................................................................87
VSS Parts Section ................................................................................................................88
Gate Rotor .....................................................................................................................89
Shaft Seal ......................................................................................................................93
Main Rotor ....................................................................................................................94
Slide Valve Cross Shafts and End Plate............................................................................96
Slide Valve Carriage Assembly .......................................................................................98
Actuator & Command Shaft.........................................................................................102
Miscellaneous Frame Components ..............................................................................104
Replacement Tools ......................................................................................................108
VSM 301-701 Replacement Parts Section ..........................................................................111
Gaterotor Assembly ....................................................................................................112
Shaft Seal ....................................................................................................................115
Main Rotor, Slide Valve Cross Shafts & End Plate ..........................................................116
Slide Valve Carriage Assembly .....................................................................................120
Actuator & Command Shaft.........................................................................................122
Miscellaneous Frame Components ..............................................................................124
Replacement Tools ......................................................................................................128
Danfoss Liquid Injection Valve Setup .................................................................................129
Appendix A: Pre Start Up for Remote Oil Coolers ...............................................................143

Standard VILTER Warranty Statement

Seller warrants the products it manufactures to be free from defects in material and workmanship for a period of
eighteen (18) months from the date of shipment from Seller’s manufacturing plant or twelve (12) months from
date of installation at the initial end users location, whichever occurs first. In addition, Seller provides the following
extended warranties: (a) three (3) years from the date of shipment on single screw compressor internal rotating
parts, (b) two (2) years from the date of shipment on reciprocating compressors and single screw and reciprocating compressor parts, and (c) two (2) years on all other parts on a single screw compressor unit. Such warranties
do not apply to ordinary wear and tear. Seller does not warrant that the product complies with any particular law
or regulation not explicitly set forth in the specifications, and Buyer is responsible for ensuring that the product
contains all features necessary to safely perform in Buyer’s and its customer’s plants and operations. Buyer must
notify Seller of any warranty claim within ten (10) days after such claim arises, otherwise Buyer waives all rights to
such claim. Products supplied by Seller, which are manufactured by others, are not warranted by Seller, but rather
Seller merely passes through the manufacturer’s warranty to Buyer.
SELLER EXPRESSLY DISCLAIMS ALL OTHER WARRANTIES, WHETHER EXPRESS OR IMPLIED, INCLUDING THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
Unless otherwise agreed in writing, Buyer’s sole remedy for breach of warranty is, at Seller’s option, the repair of
the defect, the correction of the service, or the providing a replacement part FOB Seller’s office. Seller will not be
responsible for costs of dismantling, lost refrigerant, reassembling, or transporting the product. Further, Seller will
not be liable for any other direct, indirect, consequential, incidental, or special damages arising out of a breach of
warranty. THESE WARRANTY REMEDIES ARE EXCLUSIVE AND ALL OTHER WARRANTY REMEDIES ARE EXCLUDED.
Products or parts for which a warranty claim is made are to be returned transportation prepaid to Seller’s factory.
Any improper use, corrosion, neglect, accident, operation beyond rated capacity, substitution of parts not approved
by Seller, or any alteration or repair by others which, in Seller’s judgement, adversely affects the Product, shall void
all warranties and warranty obligations. Further, Seller shall not be liable under the above warranties should Buyer
be in default of its payment obligations to Seller under this Agreement or any credit agreement.

Standard VILTER 5/15 Warranty Statement

The seller extends warranty, from date of shipment, to a period of fifteen (15) years on all compressor bearings,
five (5) years on all internal compressor parts and two (2) years on the remainder of the parts on single screw
compressor units. If within such period any such product shall be proved to Seller’s satisfaction to be defective,
such product shall be repaired or replaced at Seller’s option. Such repair or replacement shall be Seller’s sole
obligation and Buyer’s exclusive remedy hereunder and shall be conditioned upon Seller’s receiving written
notice of any alleged defect within ten (10) days after its discovery and, at Seller’s option, return of such parts to
Seller, F.O.B., freight prepaid to Seller’s factory. Expenses incurred by Buyer in repairing or replacing any defective product or any lost refrigerant will not be allowed except by written permission of Seller. This warranty is
only applicable to products properly maintained and used according to Seller’s instructions, the use of genuine
Vilter replacement parts and recommended oil in all repairs and replacements has demonstrated adherence to a
scheduled maintenance program as detailed in the Single Screw Compressor operating manual. This warranty
does not apply to normal wear and tear, or damage caused by corrosion, misuse, overloading, neglect, improper
operation, accident or alteration, as determined by Seller. Products supplied by seller hereunder, which are
manufactured by someone else, are not warranted by Seller in any way, but Seller agrees to assign to Buyer any
warranty rights in such products that the Seller may have from the original manufacturer. Labor and expenses
for repair are not covered by warranty.
THE WARRANTY CONTAINED IN THIS SECTION IS EXCLUSIVE AND IN LIEU OF ALL OTHER REPRESENTATIONS
AND WARRANTIES (EXCEPT OF TITLE), EXPRESS OR IMPLIED WARRANTY OF MERCHANTABILITY OR IMPLIED
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE.
Any description of the product, whether in writing or made orally by Seller or Seller’s agents, specifications,
samples, models, bulletins, drawings, diagrams, engineering sheets or similar materials used in connection with
Buyer’s order are for the sole purpose of identifying the products and shall not be construed as an express warranty. Any suggestions by seller or Seller’s agents regarding use, application or suitability of the products shall
not be construed as an express warranty unless confirmed to be such in writing by Seller. The 5/15 Extended
Warranty shall be applicable only if the specific maintenance guidelines as outlined in the technical manual are
followed. This includes the compressor inspections, completing periodic oil analysis and the change out of the
oil and oil filters, and related components as required with only genuine Vilter parts. The customer is required to
keep a maintenance log and receipts demonstrating the use of Genuine Vilter parts for validation of a warranty
claim, if requested.
Note: The 5/15 warranty applies to NEW compressors only, and does NOT include used or remanufactured compressors.

Long Term Storage Requirements

The procedure described is a general recommendation for long term storage (over one month of no operation)
of Vilter Manufacturing packages and compressors. While this procedure is intended to cover most of the
commonly encountered situations, it is the responsibility of the installation firm and end user to address any
unusual conditions. We suggest using the accompanying Long Term Storage Log sheet for recording purposes
to validate the appropriate procedures.
Prior to start-up, Vilter recommends that a complete system pressure check be performed. Upon verification
of the system integrity, a comprehensive evacuation procedure should be completed to ensure a dry system
before gas is introduced. The oil circuit of any compressor is to be primed at initial start-up through the prelube oil pump on screw compressors.
Warranty of the system remains in effect as described in Section 5, Product Warranty and Procedures.
*

If the unit is designed for indoor duty, it must be stored in a heated building.
If the unit is designed for outdoor duty, and is to be stored outdoors, a canvas tarp is recommended for
protection until installation is imminent. Adequate drainage should be provided, by placing wood blocks
under the base skid, so that water does not collect inside the base perimeter or low spots in the tarp.

All compressor stop valves are to be closed to isolate the compressor from the remainder of the system. All
other valves, except those venting to atmosphere, are to be open. It is essential that the nitrogen holding
charge integrity be maintained.

Cover all bare metal surfaces (coupling, flange faces, etc.) with rust inhibitor.

Desiccant is to be installed in the control panel. If the panel is equipped with a space heater, it is to be
energized. If the panel does not have a space heater, use a thermostatically controlled 50-watt light bulb.
Use an approved electrical spray-on corrosion inhibitor for panel components (relays, switches, etc.)

All pneumatic controllers and valves (Fisher, Taylor, etc.) are to be covered with plastic bags and sealed with
desiccant bags inside.

System and compressor pressures (unit is shipped with dry nitrogen holding charge approximately 5 psi
above atmospheric pressure) are to be monitored, on a regular basis, for leakage. It will be necessary to
add a gauge to monitor the system holding charge pressure. If a drop in pressure occurs, the source of
leakage must be found and corrected. The system must be evacuated and recharged with dry nitrogen to
maintain the package integrity.

Motors – (NOTE: The following are general recommendations. Consult the manufacturer of your motor
for specific recommendations.)

1) Remove the condensation drain plugs from those units equipped with them and insert silica-gel into the
openings. Insert one-half pound bags of silica-gel (or other desiccant material) into the air inlets and outlets
of drip-proof type motors.
NOTE:

The bags must remain visible, and tagged, so they will be noticed and removed when
the unit is prepared for service.

Long Term Storage Requirements

2) Cover the unit completely to exclude dirt, dust, moisture, and other foreign materials.
3) If the motor can be moved, it is suggested that the entire motor be encased in a strong, transparent plastic bag.
Before sealing this bag, a moisture indicator should be attached to the side of the motor and several bags of
silica-gel desiccant put inside the bag, around the motor. When the moisture indicator shows that the desiccant
has lost its effectiveness, as by a change in color, the bag should be opened and fresh replacement desiccants
installed.
Whenever the motor cannot be sealed, space heaters must be installed to keep the motor at least 10°F above
the ambient temperature.
NOTE:

There is a potential for damage by small rodents and other animals that will inhabit motors
in search of warm surroundings or food. Due to this, a possibility of motor winding destruction exists. Sealing motor openings should restrict access to the motor.

4) Rotate motor and compressor shafts several revolutions (approximately 6) per month to eliminate flat spots on
the bearing surfaces. If the compressor unit is installed, wired and charged with oil, open all oil line valves and run the
oil pump for 10 seconds prior to rotating the compressor shaft. Continue running the oil pump while the compressor
shaft is being turned to help lubricate the surfaces of the shaft seal.

Description

COMPRESSOR
The Vilter Single Screw Compressor is a positive displacement, capacity and volume controlled, oil flooded,
rotary compressor which uses a single main screw intermeshed by two opposing gate rotors. Gas compression
occurs when the individual fingers of each gate rotor sweep through the grooves, or flutes, of the main screw as
the screw rotates. Compression occurs from the time the screw flute is first closed off by the gate rotor finger,
until the time when the screw flute has rotated to the point of lining up with the discharge port in the compressor housing. A labyrinth type seal is used to prevent gas at discharge pressure from leaking past the end of the
screw. Any discharge gas leakage past the labyrinth seal is vented back to suction via four longitudinal holes
drilled through the body of the screw.
By venting the discharge end of the main screw back to suction, forces on each end of the screw are equal. This
results in zero net axial forces on the main bearings. With twin opposing gate rotors, all radial forces are cancelled out also. Main shaft bearings have no net forces except the weight of the screw and the shaft assembly.
The compressors are comprised of three rotating assemblies: the main screw assembly and the two gate rotor assemblies. Each of these rotating assemblies use a common bearing configuration consisting of a single,
cylindrical rolling element bearing at one end, and a pair of angular contact ball bearings at the other end. The
pair of angular contact ball bearings are used to axially fix one end of the rotating shafts, and to absorb the small
amount of thrust loads on the shafts. The inner races of the ball bearings are securely clamped to the rotating
shafts, while the outer races are securely held in the bearing housing, thus fixing the axial position of the shaft
in relation to the bearing housings. The cylindrical roller bearings at the opposite end of the shafts allow for
axial growth of the shafts while supporting the radial loads from the shafts.
The suction gas enters the compressor housing through the top inlet flange, at the driven end of the unit. The
driven end of the compressor housing is flooded with gas at suction pressure. The gas enters the open end of
the main screw flutes at the driven end, and becomes trapped in the screw flute as the screw rotates and the
gate rotor tooth enters the end of the flute. At this point, the compression process begins. Directly after the
screw flute is closed off by the gate rotor tooth, oil is injected into the groove.
The oil enters the compressor through a connection at the top of the compressor. The purpose of the injected oil
is to absorb the heat of compression, to seal the gate rotor tooth in the groove, and to lubricate the moving parts.
Additional internal oiling ports are provided at the main and gate rotor bearings to cool and lubricate the bearings. The mechanical shaft seal housing also contains oiling ports to lubricate, cool and provide a sealing film
of oil for the mechanical shafts seal. Excess oil flows through the check valves on the sealing baffle plate. This
oil is directed at the main rotor roller bearing, which cools and lubricates the front roller bearing.
As the main screw rotates, the gate rotor is also driven, causing the gate rotor tooth to sweep the groove in the
main screw. This sweeping action reduces the volume of the groove ahead of the gate rotor tooth and causes
the trapped gas and oil to be compressed in the reduced volume. As the main screw continues to rotate, the
gate rotor tooth continues to reduce the groove volume to a minimum, thus compressing the trapped gas to
a maximum pressure. A labyrinth seal arrangement prevents the compressed gas from leaking past the end of
the screw. As the gate rotor tooth reaches the end of the groove, the groove rotates to a position that lines up
with the discharge port in the compressor housing and the gas/oil mixture is discharged from the screw at high
pressure. This completes the compression cycle for a single flute of the main screw.
Once the gas is swept from the main screw flute through the discharge port, it passes into the discharge manifold
of the compressor. From the discharge manifold, the gas/oil exits the compressor housing

Description

The Vilter compressors feature the exclusive Parallex™ Slide System, which consists of a pair of slides for each
gate rotor assembly. These two independently operated slides are referred to as the capacity slide and the volume ratio slide. On the suction end of the screw, the capacity slide moves to vary the timing of the beginning
of the compression process. With the slide moved all the way out to the suction end of the screw (the 100%
position), the compression process begins immediately after the gate rotor tooth enters the screw flute and
closes off the end of the groove. In this situation, the maximum volume of gas is trapped in the screw flute at
the start of the compression process. As the slide is pulled back away from the suction end of the screw, the
start of the compression process is delayed as some of the suction gas is allowed to spill back out of the screw
flute until the screw rotates far enough to pass the end of the capacity slide and begin compressing. This causes
a reduced volume of gas to be trapped in the screw flute when the compression process begins. In this way, the
capacity of the compressor is reduced from 100% down to as low as 10% of the full rated capacity.
The capacity slide provides the means for controlling specific process set points. By continuously adjusting the
flow of gas through the compressor, either suction or discharge pressure in a particular process can be controlled.
When coupled with a microprocessor controller, the adjustable capacity slide allows for precise and continuous
automatic control of any parameter in the process to a chosen set point.
The second slide for each gate rotor is the volume ratio slide. The purpose of the volume ratio slide is to maximize
the efficiency of the compressor by matching the gas pressure within the screw flute at the point of discharge
to the downstream process requirements. The volume ratio slide operates at the discharge end of the screw,
and acts to vary the position of the discharge port. When the slide is extended fully to the discharge end of the
screw (the 100% position), the compression process within the screw flute continues until the screw rotates
far enough for the flute to pass the end of the volume ratio slide. At this point, the screw flute lines up with the
discharge port and the compressed gas is expelled from the screw flute. As the volume ratio slide is pulled back
away from the discharge end of the screw, the position of the discharge port is changed and the gas is allowed
to escape the screw flute earlier in the compression process, at a reduced pressure.
The overall volume ratio within the compressor is determined by the distance between the front of the capacity slide (the start of compression) and the back of the volume ratio slide (the completion of compression).
Therefore, the volume ratio slide must respond to changes in the downstream pressure measured in the oil
separator and position itself for the required compression ratio based on the position of the capacity slide. By
only compressing the gas within the screw as far as required to match the pressure in the downstream receiver,
the compressor efficiency is maximized. Proper positioning of the volume ratio slide prevents either over
compressing or under compressing of the gas within the screw flute. This allows the single screw compressor
to efficiently handle a range of volume ratios from as low as 1.2 up to 7.0.

Foundation
Introduction
Vilter Single Screw compressor units are low vibration machines. Under most conditions, no elaborate foundation is
necessary. However a sound foundation maintains motor alignment and proper elevation, and is therefore required.
Provided are recommendations for the foundation and anchoring of the compressor unit. The Vilter foundation supports the entire operating weight of the unit and is suitable for years of continuous duty. Included are specifications
for concrete, rebar, aggregate, anchors and grout.
Considerations Prior to Starting
Consult professionals, such as building inspectors, structural engineers, geotechnical engineers and/or construction
contractors prior to starting. Below are a few points to consider:
Site Characteristics:
• Soil information
• Site drainage
• Wind data
• Seismic zone
• Ingress and egress
• Power and power lines
Site Layout:
• Plant elevations, grading, drainage and erosion
• Accessibility to compressors for service
• Location of surrounding buildings
• Property lines and roadways
• Power
• Fire safety
Safety:
NOTE
Always check with a safety engineer before proceeding.
•
•
•
•
•
•

Arranging equipment with adequate access space for safe operation and maintenance
Wherever possible, arrange equipment to be served by crane. If not feasible, consider other handling methods
Make all valves and devices safely accessible
Use special bright primary color schemes to differentiate service lines
Lightening protection for outdoor installations
Relief valve venting

Foundation Materials
Materials needed to build the foundation are forms, concrete, sand, rebar, wire, grout, anchor bolts, expansion board
and shims. A set of concrete forms will need to be acquired; generally, these can be rented or constructed from
dimensional lumber. There should be enough 4,000 psi concrete with one inch aggregate to build the foundation.
Also, there should be enough sand to provide a base of compacted sand four inches thick for the foundation to rest
on, see Figure 1 - Concrete Pad with Compressor Unit Dimensions - Side View. The rebar required is ASTM 615, grade
60, sizes #4 and #6. Wires will also be needed to tie the rebar together. The recommended grout is Masterflow 648CP
high performance non-shirk grout to provide at least a 1” thick pad under each foot. The recommended anchors are
5/8” Diameter HILTI HAS SS threaded rod for outdoor installations or HAS-E rods for indoor installations. Anchor bolts
shall have a five inch projection and 12-3/8” embedment. The required adhesive is HIT-ICE/HIT/HY 150 anchoring
system. There should be enough one inch expansion boards to go around the perimeter of the foundation. Finally
there should be enough shim stock and extra anchor bolt nuts to level the compressor unit.

Foundation
Building the Foundation
Use the Vilter General Arrangement (GA) and foundation drawings to help secure a building permit and foundation
construction. The Vilter GA drawing will have the necessary dimensions required to determine the overall foundation size and where to locate the compressor unit on the foundation. It will also show the dimensions required to
form up the housekeeping piers that the compressor unit rests on. The Vilter foundation drawing lists the necessary
information to construct a suitable foundation. It includes the rebar requirements and locations. It also shows anchor
bolt locations, grouting and the concrete specifications. Using the Vilter GA drawing, Vilter foundation drawing and
the information from site characteristics, site layout and safety studies will provide enough data to allow building
the foundation to proceed.
The foundation is to be cast and permanently exposed against the earth. Therefore, if constructing on an existing
floor, typically indoors, the floor will need to be broken up to get to the earth. If starting from undisturbed soil, it
must be also be prepared accordingly. In either case, these are some check points to consider:
• Check the depth of your frost line to ensure the foundation extends below it
• Ensure the foundation rests entirely on natural rock or entirely on solid earth, but never on a combination
of both
• Check the ability of the soil to carry the load
• Check wet season and dry season soil characteristics for static loading limits and elasticity
• Check local codes for Seismic Design requirements
For examples of foundation diagrams, refer to Figure 1 - Concrete Pad with Compressor Unit Dimensions - Side View
and Figure 2 - Concrete Pad with Compressor Unit Dimensions - Front View
G.A.
G.A.

COMPRESSOR UNIT

2" (TYP.)

EL. TOP OF
GRADE

4" COMPACTED
SAND

3" CLR.

1'-0"

2" CLR.

CENTER LINE OF
GAS COMPRESSION
SYSTEM

# 6 @ 12"
EACH WAY
TOP & BOTTOM
EXCAVATE TO FROST DEPTH AS REQ'D AND BACKFILL
WITH CLSM OR NON-FROST SUSCEPTIBLE FILL

Figure 1. Concrete Pad with Compressor Unit Dimensions - Side View

Foundation
G.A.
G.A.

COMPRESSOR UNIT
CENTER LINE OF
GAS COMPRESSION
SYSTEM

EL. TOP OF
GRADE

# 6 @ 12"
EACH WAY
TOP & BOTTOM
EXCAVATE TO FROST DEPTH AS REQ'D AND BACKFILL
WITH CLSM OR NON-FROST SUSCEPTIBLE FILL

Figure 2. Concrete Pad with Compressor Unit Dimensions - Front View
Once the site has been excavated and prepared, place four inches of sand down on the bed where the foundation will
rest. The sand must be compacted before placing the forms and rebar. After the sand is compacted, use the Vilter GA
drawing to construct the forms for the foundation. With forms in place, install expansion boards on the inside of the
forms, for example, see Figure 3 - Interior Foundation Isolation. Next, place your rebar in the forms as per the Vilter
foundation drawing. When all rebars are in place the concrete can be poured. The concrete must then be trolled level
and a surface texture etched in place. Leave the concrete to cure for at least 28 days.

COMPRESSOR UNIT
FOUNDATION

ISOLATION JOINT,
1" MINIMUM
THICKNESS

CHAMFER EDGE

6”

Figure 3. Interior Foundation Isolation

CONCRETE
SLAB IN
BUILDING

Foundation
Compressor Unit Installation
Once the foundation has cured, the compressor unit can be placed on the foundation, see Figure 4. Foundation with
Housekeeping Pads Dimensions - Top View and Figure 5. Housekeeping Pad Dimension Detail - Top View. With the
appropriate material handling equipment, lift the compressor unit by locations shown on the Vilter GA drawing and
slowly place it on the foundation housekeeping piers. As per the Vilter GA drawing, ensure the compressor unit is
correctly placed on the foundation. Once placed, use the spherical washers directly under the compressor as the
surface to level the compressor unit, see Figure 6 - Compressor with Spherical Washers. Place shims under the feet
of the compressor unit, as needed, until it is leveled, see Figure 7 - Concrete Pad Housekeeping Detail. Select the
correct drill bit and drill thru the anchor bolt hole in the mounting feet of the compressor unit to the depth called
for on the Vilter foundation drawing. Finally using the HILTI instructions, put your anchor bolts in place and wait for
them to cure. Then place the nuts on the anchor bolts to finger tight and prepare to grout.

5'-0"

10'-0"

OVER ALL G.A. LENGTH + 4'-0"

CENTER LINE GAS
COMPRESSION
SYSTEM

Figure 4. Foundation with Housekeeping Pads Dimensions - Top View

Foundation
1" (TYP.)
G.A.

G.A.

CENTER LINE

G.A.

G.A. + 2"

G.A.

(2) - # 4
CLOSED TIES

(5) - # 6 VERT.
WITH STD. 90° HOOK
AT BOTTOM EACH
FACE

5/8" DIA. HILTI HAS SS THREADED ROD
(HAS-E RODS ARE ACCEPTABLE FOR INTERIOR
INSTALLATIONS) INSTALLED USING
HIT-ICE/HIT-HY 150 ADHESIVE ANCHORING
SYSTEM.
(5" PROJECTION, 12 3/8" EMBEDMENT.)
HOLES TO BE INSTALLED WITH HAMMER DRILL.
DO NOT DIAMOND CORE. (TYP.)

Figure 5. Housekeeping Pad Dimension Detail - Top View

SPHERICAL

WASHER

SPHERICAL
WASHER

Figure 6. Compressor with Spherical Washers

Foundation
70+6.')
*1.&&190076

010Ä5*4+0-
'21:;)4176

9#5*'4

/+0

.'8'.+0)076

4'%1//'0&'&
(14
*175'-''2+0)

#0%*14$1.6

%10%4'6'
$#5'
Figure 7. Concrete Pad Housekeeping Detail

Leveling and Grouting
The unit should be level in all directions. Wet the concrete pad according to the grout manufacturer’s directions. Mix
a sufficient amount of grout. The grout must be an expanding grout rather than shrinking to provide a tighter bond.
Follow the manufacturer’s recommendations for setting, precautions, mixing, and grout placement, finishing and
curing. The grout must be worked under all areas of the feet with no bubbles or voids. If the grout is settled with a
slight outside slope, oil and water can run off of the base. Once the grout has cured, torque the anchor bolts as per
HILTI instructions.
Piping Connections
Piping Stress
Once the screw compressor package has been installed, properly grouted and anchored, it is imperative that the
piping bolted to the screw compressor not impose excessive forces on the compressor. Suction and discharge lines
should be supported so the lines will not move if disconnected from the compressor.
Additional Information
Codes and Standards
Vilter followed the following codes and standards when designing your foundation:
• ACI
• ASTM
• ASCE 7
• IBC 2006

Foundation
Operation and Performance
The foundation was designed for:
• Outside environment severe exposure
• Ambient temperature -10 degrees F to 105 degrees F
• Unit weight 20,000 lbs
• RPM 3600
• Soil bearing capacity 1,500 lbs/sq.ft.
• Wind speed 120 MPH
• Exposure factor D
• Wind importance factor 1.15
• Concrete poured on and permanently cast against the earth
General Design Requirements
The compressor foundation is designed to:
• Maintain the compressor in alignment and at proper elevation.
• Minimize vibration and prevents its transmission to other structures
• Provide a permanently rigid support
• Provide sufficient depth to dampen vibrations.

Rigging and Lifting

Thank you for purchasing a gas compressor (the “Compressor”) from Vilter Manufacturing LLC (“Vilter”). Rigging
and Lifting a large piece of equipment like the Compressor is extremely dangerous.
**DISCLAIMER**
Notice
This rigging and lifting manual (this “Manual”) is provided to you as a courtesy by Vilter and is not intended to be a
comprehensive guide to rigging and lifting the Compressor. Vilter shall not be liable for errors contained herein or
for incidental or consequential damages (including any injury to persons performing the rigging or lifting) in connection with the furnishing, performance, or use of this Manual. This Manual is only a set of suggestions and you
may not rely solely on the information contained in this Manual to conduct the lift. In addition, information in this
Manual is subject to change without notice.
Limited Warranty
The information is this Manual does not constitute any warranty as to the Compressor. The warranty provision
contained in the terms and conditions pursuant to which the Compressor was sold serves as the sole and exclusive
warranty.
Safety
To correctly and safely operate the Compressor, you must consult all of the documentation that was provided to
you with the purchase of the Compressor (including all information sheets, warning notices and any other documents). This Manual is not intended to summarize or supplant any directions regarding how to safely operate or
move the Compressor.
BEFORE LIFTING AND RIGGING THE COMPRESSOR
In order to minimize the inherent risk involved in rigging and lifting a large piece of equipment, before attempting
to lift the Compressor, the actions of all parties involved in the lift must be carefully planned.
The following is provided merely to encourage purchasers to think about all of the steps necessary to rig and lift
the Compressor. Vilter can neither anticipate all of the dangers involved in a particular lift, nor evaluate the particular capabilities of each of person who will participate in the lift.
Educate and Select Lift Participants
To rig and lift the Compressor in a safe manner, you will need to select experienced, trained people (“Participants”)
to take on (and successfully perform) at a minimum the tasks associated with each of the following positions:
•
•
•
•
•
•
•

Crane Operator;
Crane Owner;
Lift Coordinator;
Lift Engineer;
Rigging Specialist;
Riggers; and
Safety Signaler.

Rigging and Lifting

Training curriculum for Participants, at a minimum, should include:
•
•
•
•
•
•
•

A review of safe operating practices;
A review of who each person is and their specific role in the lift;
A tutorial on how to read lift charts;
A demonstration on how to use and inspect rigging hardware;
A review of the company’s general lift plans and procedures;
A tutorial on hand signals normally used to communicate with crane operators (a copy of such hand signals
may be obtained from machine safety vendors); and
A review of the Compressor’s specific rig and lift plan (the “Plan”) (developed by the Lift Coordinator and Lift
Engineer); please see the section immediately below entitled “Create and Communicate the Plan.”

Individuals participating in the lift should fully understand the scientific principles pursuant to which a successful
lift is dependent—for example, center of gravity, equilibrium, and mechanics of load stabilization, critical angle
considerations and force.
All Participants should undergo a fitness-for-duty program, including drug testing and medical examinations.
Create and Communicate the Plan
Well in advance of the planned lift date, lift planning meetings and hazard assessment meetings should be held
with all Participants in attendance. In addition, the Plan should be finalized and distributed for review and comment.
The Plan should clearly define requirements, expectations and specifications for lifting the Compressor. At a minimum, the Plan should include:
•
•
•
•
•
•
•
•

Standard lifting and rigging procedures in place at the lift site (including proper classification of the lift as a
“critical lift” a “serious lift” or a “standard lift”);
Drawings of the Compressor;
A description of the lifting task;
An evaluation of the hazards;
The rigging plan and sketches of rigging to be attached to the Compressor;
The roles and responsibilities of all Participants;
An emergency plan; and
The contact information of the Plan preparer

It is important to confirm that each Participant understands both the broader Plan and their specific responsibilities
during the lift. Participants should be encouraged to contact the Plan preparer at any time if they have questions.
In addition, the Plan preparer should be on-site during the lift to ensure that the lift is being executed in accordance with the Plan. Finally, well in advance of the lift date, it should be confirmed that all necessary permits have
been obtained.
Inspect and Use the Appropriate Lifting Equipment
Verify Crane Operator and Crane Owner Credentials
Prior to rigging and lifting the Compressor, certain precautions should be taken with regards to the crane, the
crane operator and the crane owner.
• The lift capacity of the crane must exceed the Compressor’s weight;
• Confirm that the crane operator is qualified to work on the site;

Rigging and Lifting

•
•
•
•

Get third-party confirmation that the crane owner and the crane operator are in compliance with applicable
laws, regulations and internal safety standards;
Consult with the crane owner to determine if any site preparation is required for outriggers—improper use of
outriggers is a significant cause of crane failure;
Determine the level of supervision to be supplied by the crane owner; and
Review all crane maintenance and inspection records, including without limitation, the crane log book, maintenance records, inspection reports and the physical condition of the crane.

Take all Appropriate Measurements
• Understand and interpret the load charts;
• Review all Compressor drawings for unit size, weight, center of gravity and other specifications;
• Communicate incident response procedures in writing prior to the lift and verbally immediately before the lift;
• Determine the initial position, final position, orientation and elevation of the Compressor;
• Ensure that adequate space is provided to safely assemble, erect, and operate the crane and materials (such as
timber mats, cribbing and blocks);
• Identify and communicate to all Participants the access points, lift radius, swing radius, clearances, and obstructions;
• Eliminate hazards and obstructions that may interfere with moving the Compressor; and
• Inform all Participants of water lines, sewer lines, power lines and other obstructions.
Use Proper Rigging Methods
• Determine diameter, length and quantity of necessary rigging hardware (design and detail the rigging hardware to suit lifting the Compressor at the supplied pad eyes);
• Review and inspect all hoisting, lifting and rigging equipment;
• Select shackle size and prepare sketches or drawings for rigging;
• Use proper, conservative rigging techniques—including spreader beams—needed to lift the Compressor;
• Pad sharp corners, check the orientation of chocker hitches and the orientation of hooks;
• Prevent the binding of hoist rings; and
• Verify pad eye information.
TEST AND BALANCE THE COMPRESSOR
It is essential to test and balance the compressor before executing the actual lift in order to identify potential
causes of injury to Participants and the Compressor.
Secure Rigging and the Lift Site
• Reiterate that no one should walk under the raised load;
• Secure and restrict access to the lift area (consider vacating all non-essential personnel from the area);
• Provide qualified supervision for the duration of the lift;
• If applicable, assess the weather conditions and decide if it is safe to proceed;
• Stop the lift when any potentially unsafe conditions are recognized; and
• Ensure there are open channels for communications during the pre-lift, lift and post-lift phases (radio communications should be used if a direct line of sight is not possible).
Test and Balance the Compressor before the Lift
• Slowly raise the crane to take slack out of the rigging without actually lifting the load;
• Allow the rigging gear to settle into place;
• Check for twists and binds;
• Verify that all padding has remained in place and that all slings are protected from sharp edges;
• Begin to raise the load to verify balance and check the braking system; and
• If the Compressor is not balanced, lower and adjust as necessary.

Rigging and Lifting

CONTACT VILTER
While Vilter will not offer any specific feedback on the Plan or provide a specific Plan for rigging and lifting the
Compressor, Vilter may be able to answer questions about the Compressor that are important in developing your
Plan.
Please contact Vilter at:
P.O. Box 8904
5555 S Packard Ave
Cudahy, WI 53110-8904
Telephone: 1-414-744-0111
Fax: 1-414-744-3483
email: info.vilter@emerson.com
www.vilter.com

Installation

DELIVERY INSPECTION

II.

Vilter screw compressor components are thoroughly inspected at the factory, assuring the
shipment of a mechanically perfect piece of equipment. Damage can occur in shipment, however.
For this reason, the units should be thoroughly
inspected upon arrival. Any damage noted should
be reported immediately to the transportation
company. This way, an authorized agent can examine the unit, determine the extent of damage
and take necessary steps to rectify the claim with
no serious or costly delays. At the same time,
the local Vilter representative or the home office
should be notified of any claim made.
TABLE 1.

UNIT WEIGHTS (LBS)*

MODEL

STANDARD

ECON-OMIZER

VSM 71
VSM 91
VSM 101
VSM 151
VSM 181
VSM 201
VSM 301
VSM 361
VSM 401
VSM 501
VSM 601
VSM 701
VSS 451
VSS 601
VSS 751
VSS 901
VSS 1051
VSS 1201
VSS 1301
VSS 1501
VSS 1801
VSS 1551
VSS 1851
VSS 2101

2,750
2,750
2,750
2,750
2,750
2,750
2,850
2,850
2,850
4,000
4,500
5,000
4,000
4,500
5,300
5,300
6,600
6,700
6,750
10,010
10,010
11,000
11,000
11,000

* Does not include motor.

FOUNDATIONS

Vilter single screw compressor units are basically vibration free machines, therefore, no
elaborate foundations are necessary. The floor
or foundation upon which the unit will be placed
should be designed to support the entire operating weight of the unit. See Table 1 for unit
weights. See Foundation, page 12, for additional
foundation instructions.
III.

LOCATING UNIT - DRIVE
COUPLING ALIGNMENT

The single screw compressor units are shipped
with all major components mounted on structural steel. Place the entire unit on the floor
on a concrete pad and securely bolt in place.
Review local codes and ASHRAE Safety Code for
Mechanical Refrigeration. Bolt holes are located
in the unit’s mounting feet. When locating the
unit, provide adequate space for service work.
When the compressor unit is in place on the concrete pad, check both lengthwise and crosswise
to assure it is level. Use shims and wedges as
needed under the mounting feet to adjust the
level of the unit.
On single screw units, the motor and compressor have been roughly aligned at the factory.
The coupling center section was shipped loose
to allow a check of proper electrical phasing,
direction of rotation of the motor and final
coupling alignment. The dial indicator alignment method is recommended. Final alignment
should be within 0.004 inches total indicator
reading in all direction for the VSS models and
0.010 inches for the VSM models.
III.

SYSTEM PIPING

Refer to the ANSI/ASME B31.5 Code for Refrigeration Piping. All compressor oil supply and oil
return piping has been completed at the factory.
The necessary connections to be made to the
screw compressor unit will vary depending on
the type of oil cooling method purchased. Main
line refrigerant suction and discharge connections are always necessary.

Installation

Care must be taken to avoid trapping the lines except for specific purposes. When traps are used,
the horizontal dimensions should be as short as
possible to avoid excessive oil trapping.
Lines for ammonia systems must be of steel pipe
with specially designed ammonia service fittings.
Common pipe fittings must NEVER be used as
they will not provide the same service. Steel pipe
is generally used in large installations when joints
are welded.
In making up joints for steel pipe, the following
procedures should be followed:
For threaded connections, all threads on the pipe
and fitting should be carefully cleaned to remove
all traces of grease or oil. Threads should then be
wiped dry with a lintless cloth. Only thread filling compounds suitable for refrigeration service
should be used for making steel pipe joints. These
compounds should be used sparingly, and on the
pipe only. Do not put any on the first two threads
to prevent any of the compound from entering
the piping system. Acetylene or arc welding
is frequently used in making steel pipe joints,
however, only a skilled welder should attempt this
kind of work. Take care to see no foreign materials
are left in the pipes and remove all burrs formed
when cutting pipe.
It is important to avoid short, rigid pipe lines that
do not allow any degree of flexibility. This must
be done to prevent vibration being transmitted
through the pipe lines to the buildings. One
method of providing the needed flexibility to
absorb the vibration is to provide long lines that
are broken by 90° Ells in three directions.

for tube sizes not larger than 1-3/8” in outside
diameter. These requirements are in accordance
with the mechanical code for refrigeration ANSI
B9.1-1971. The type of copper tubing to be used
for a given pressure is dependent on the strength
of the copper at the design temperature. Some
local codes forbid the use of Type “L”. Therefore,
before installation, be sure to check local requirements. Never use type “M” as it does not have
adequate wall thickness to withstand the operating pressures. In selecting fittings for Halocarbon
piping, only wrought copper fittings should be
used. Cast fittings as used for water service are
porous and will allow the refrigerant to escape.
Note this exception: In larger pipe sizes, wrought
fittings are not available. However, specially
tested cast fittings are available and these may
be used with complete safety.
In larger pipe sizes, wrought fittings are not available. However, specially tested cast fittings are
available and these may be used with complete
safety.
When soldering copper tubing joints, only silver
solder should be used for Refrigerant-22 service.
Soft solder such as “50-50” should never be used,
as its melting point is too low, lacks mechanical
strength, and tends to break down chemically in
the presence of moisture.
A second method would be to install flexible
pipe couplings as close to the compressor unit
as possible with connections run in two different
directions, 90° apart. These flexible connections
should be installed on both the high and low side
lines of the compressor unit.

Smaller Halocarbon and Hydroflourocarbon
installations use copper pipes with solder type
fittings where possible. The use of screw type
fittings in Halocarbon systems should be held
to an absolute minimum, as these refrigerants,
due to their physical properties, will leak through
screw type joints.

Hangers and supports for coils and pipe lines
should receive careful attention. During prolonged operation of the coils, they may become
coated with ice and frost, adding extra weight to
the coil. The hangers must have ample strength
and be securely anchored to withstand the
vibration from the compressor and adequately
support the pipe lines.

When drawn copper tubing is used for Halocarbon lines, type “K” or “L” conforming to ASTM
B88 should be used. Soft annealed copper tubing conforming to ASTM B280 can also be used

Water supply and drain connections, and equipment using water, should be installed so all the
water may be drained from the system after
the plant has been shut down in cold weather.

Installation

These precautions will avoid costly damage to
the equipment due to freezing.
This information is taken from ASHRAE 15-89 and
ANSI B31.5. The installing contractor should be
thoroughly familiar with these codes, as well as
any local codes.
IV.

ELECTRICAL CONNECTIONS

The single screw compressor units are shipped
with all package mounted controls wired. The
standard control power is 115 volts 60 Hertz,
single phase. If a 115 volt supply is not available, a
control transformer may be required. The power
source must be connected to the control panel
according to the electrical diagrams.
The units are shipped without the compressor
motor starter. Field wiring is required between
the field mounted starters and package mounted
motors.
Additional control wiring in the field is also required. Dry contacts are provided in the control
panel for starting the screw compressor motor.
These contacts are to be wired in series with the
starter coils. A current transformer is supplied
along with the compressor unit, and is located
in the motor junction box. This transformer is to
be installed around one phase of the compressor motor starter. A normally open auxiliary
contact from the compressor motor starter is
also required.
Terminal locations for this wiring can be found
on the wiring diagram supplied with this unit.
Additional aspects of the electrical operation of
the single screw units are covered in the start up
and operation section of this manual.
V.

TESTING REFRIGERATION
SYSTEM FOR LEAKS

Vilter equipment is tested for leaks at the factory.
One the most important steps in putting a refrigeration system into operation is field testing for
leaks. This must be done to assure a tight system
that will operate without any appreciable loss of
refrigerant. To test for leaks, the system pressure must be built up. Test pressures for various

refrigerants are listed in ANSI B9.1-1971 code
brochure entitle “Safety Code for Mechanical
Refrigeration”. These pressures will usually suffice, however, it is advisable to check local codes
as they may differ. Before testing may proceed,
several things must be done.
First, if test pressures exceed the settings of
the system, relief valves or safety devices, they
must be removed and the connection plugged
during the test. Secondly, all valves should be
opened except those leading to the atmosphere.
Then, open all solenoids and pressure regulators by the manual lifting stems. All bypass
arrangements must also be opened. Because
of differences in characteristics of the various
refrigerants, two different testing methods are
necessary.
A.

Ammonia Systems

Dry nitrogen may be used to raise the pressure
in an ammonia system to the proper level for
the test. The gas may be put into the system
through the charging valve or any other suitable
opening. Adjust the pressure regulator on the
bottle to prevent over-pressurization. Do not
exceed the pressure rating on the vessel with
the lowest pressure rating.
Carbon Dioxide should NOT be used as a testing gas in a system where ammonia is already
dissolved in any moisture remaining. This will
cause ammonium carbonate to precipitate
when the CO2 is added. If heavy enough, this
precipitate may cause the machine to freeze
and clog the strainer.
A mixture of four parts water to one part liquid
soap, with a few drops of glycerin added, makes
a good solution. Apply this mixture with a one
inch round brush at all flanges, threaded joints,
and welds. Repair all visible leaks. If possible,
leave the pressure on over night. A small pressure drop of 5 lbs. Over this period indicates a
very tight system.
Remember to note the ambient temperature,
as a change in temperature will cause a change
in pressure.
After the system is thoroughly tested, open all

Installation

valves on the lowest part of the system so the gas
will float away from the compressor. This prevents any dirt or foreign particles from entering
the compressor and contaminating the working
parts. The oil should then be charged into the
compressor.
Charge a small amount of ammonia into the system and pressurize the system to its respective
design pressure. Pass a lit sulfur stick around all
joints and connections. Any leaks will be indicated by a heavy cloud of smoke. If any leaks are
observed during this test, they must be repaired
and rechecked before the system can be considered tight and ready for evacuation.
B.

Halocarbon Refrigerant Systems

“Oil pumped” dry nitrogen, or anhydrous CO2 in
this order of preference may be used to raise the
pressure to the proper level for testing.
When the proper pressure is attained, test for
leaks with the soap mixture previously described.
After all leaks are found and marked, relieve the
system pressure and repair the leaks. Never attempt to repair soldered or welded joints while
the system is under pressure. Soldered joints
should be opened and re soldered.
Do not simply add more solder to the leaking
joint. After all the joints have been repaired and
the system is considered “tight” the system may
be tested with refrigerant.
Attach a drum of the refrigerant to be used in the
system and allow the gas to enter until a pressure
of 5 psig is reached.
Remove the refrigerant drum and bring the
pressure to the recommended test level with oil
pumped dry nitrogen or CO2. Then check the
entire system again for leaks, using a halide torch
or electronic leak detector. Be sure to check all
flanged, welded, screwed and soldered joints, all
gasketed joints, and all parting lines on castings.
If any leaks are found, they must be repaired and
rechecked before the system can be considered
tight again, remembering that no repair should
be made to welded or soldered joins while the
system is under pressure.

Evacuating The System

A refrigeration system operates best when only
refrigerant is present. Steps must be taken to
remove all air, water, vapor, and all other noncondensables from the system before charging it
with refrigerant. A combination of moisture and
refrigerant, along with any oxygen in the system,
can form acids or other corrosive compounds that
corrode internal parts of the system.
To properly evacuate the system, and to remove
all non-condensables, air and water vapor, use a
high vacuum pump capable of attaining a blanked
off pressure of 50 microns or less. Attach this
pump to the system and allow it to operate until
system pressure is reduced somewhere below
1000 microns. Evacuation should not be done
unless the room temperature is 60F or higher.
Attach vacuum gauge(s), reading in the 20 to
20,000 micron gauge range, to the refrigerant
system. These gauge(s) should be used in conjunction with the high vacuum pump. The reading from the gauge(s) indicates when the system
has reached the low absolute pressure required
for complete system evacuation.
Connect the high vacuum pump into the refrigeration system by using the manufacturer’s
instructions. Connect the pump both to the high
side and low side of the system, to insure system
evacuation. Attach the vacuum gauge to the
system in accordance with the manufacturer’s
instructions.
A single evacuation of the system does not satisfactorily remove all of the non-condensable, air
and water vapor. To do a complete job, a triple
evacuation is recommended.
When the pump is first turned on, bring system
pressure to as low a vacuum level as possible, and
continue operation for 5 to 6 hours.
Stop the pump and isolate the system. Allow
the unit to stand at this vacuum for another 5 to
6 hours. After this time, break, the vacuum and
bring the system pressure up to 0 psig with dry
nitrogen.

Installation

To begin the second evacuation, allow the pump
to operate and reduce the pressure again to
within 50 to 1000 microns. After this reading is
reached, allow the pump to operate 2 or 3 hours.
Stop the pump and let the system stand with
this vacuum. Again using dry nitrogen, raise the
system pressure to zero.
For the third evacuation, follow the previous
procedure with the pump operating until system
pressure is reduced below the 1000 micron level.
Run the pump an additional 6 hours and hold the
system for approximately 12 hours at low pressure. After this, again break the vacuum with dry
nitrogen and allow the pressure in the system
to rise slightly above zero pounds (psig). Install
new drier cartridges and moisture indicators.
Charge the system once more below the 1000
micron level and use the refrigerant designed
for the system.
When properly evacuating the system as outlined
above, the system is dry, oxygen-free and free of
non-condensables. The piping should not be insulated before the evacuation process is started.
If moisture is in the system before evacuating, it
condenses in low places and freezes. If this happens, it can be removed by gently heating the
trap farthest away from the vacuum pump. This
causes the ice to melt and water to boil. Water vapor collects in the next trap towards the vacuum
pump. This process should be repeated until all
pockets of water have been boiled off, and the
vacuum pump has had a chance to remove all the
water vapor from the system.
VI.

UNIT OIL CHARGING

The compressor unit is shipped from Vilter with
no oil charge. The initial oil charge can be made
through the drain valve at the oil receiver/separator. Vilter motor driven and manually operated
oil chargers are available for this purpose. Once
the unit has been started and is operating above
50% capacity, oil may have to be added to bring
the oil level to the normal operating point. With
the unit operating, oil should be added through
the charging connection at the suction strainer.
The normal operating level is between the (2)
sight glasses on the oil separator. See Table 2 for
approximate oil charge requirements.

TABLE 2.

OIL CHARGE

Oil Separator Size

Approximate Oil
Charge (Gallons)

VSR 16”
VSR 20”
VSM 20”
VSM 30”
20”
24”
30”
36”
42”

20 to 27
22 to 31
20 to 25
30 to 35
30 to 40
40 to 50
60 to 75
95 to 105
145 to 165

The oil level may be above the top sight glass
at this time. Later, when the unit is placed in
operation, there will be some drop in the oil level
as the various oil lines, oil filter and other piping
becomes charged with the normal amount of
oil that will be in circulation. This drop in oil
level should bring the level in the oil receiver/
separator into the normal operating range. Do
not mix oils.
A.

Oil For Single Screw Compressors

Due to the need for adequate lubrication, Vilter
recommends only the use of Vilter lubricants,
designed specifically for Vilter compressors.
With the extensive research that has been performed, we are able to offer refrigerant specific
lubricating oils. Use of oil not specified or supplied by Vilter will void the compressor warranty.
Please contact your local Vilter representative or
the Home Office for further information.
VII.

SYSTEM REFRIGERANT CHARGING
CAUTION

When charging the system, make sure the
compressor unit is pressurized from the discharge side of the compressor. Pressurizing the
compressor from the suction side may cause
rotation of the compressor, without oil supply,
which could lead to internal damage.

Installation

After the system is leak-free and evacuation has
been completed, it is ready for charging. Before
actual charging, however, the entire operation
of the refrigeration system should be inspected
as outlined below:
A.
1.
2.
3.
4.
5.
6.
7.
8.
B.
1.
2.
3.
4.
5.
6.
C.
1.
2.
3.
4.
5.
D.

Fans on air handling equipment running.
Pumps on water cooling equipment running.
Proper location and attachment of thermostatic expansion valve bulb to suction line.
Correct fan and pump rotation.
Evaporator pressure regulators and solenoid
valves open.
Water pumps and motors correctly aligned.
Belt drives correctly aligned and tensioned.
Proper voltage to motors.

Connect a full drum of refrigerant to the
liquid charging valve. This valve is generally located in the liquid line immediately
after the king or liquid line valve. Purge the
air from the charging line.

Invert the refrigerant drum if the drum is
not equipped with “Liquid” and “Vapor”
valves, and place in such a position so the
liquid refrigerant only can enter the system. Close the liquid line or king valve, if
it is not already closed. Open the “Liquid”
charging valve slowly to allow refrigerant
to enter the system. The vacuum in the
system will draw in the refrigerant.

Compressors
Proper oil level.
Voltage agrees with motor characteristics.
Properly sized motor fuses and heaters.
Direct drivers aligned and couplings tight.
All suction and discharge valves open.
All transducers and RTD’s calibrated and
reading correctly.

It is important that, during this operation,
air handling units be running and water is
circulating through the chillers. The low
pressures on the system can cause the
refrigerant to boil at low temperature and
possibly freeze the water if it is not kept
circulating.

Condensers
Water available at water cooled condensers
and supply line valve open.
Water in receiver of evaporative condenser
and makeup water available.
Correct rotation of pump and fan motors.
Belt drives aligned and tensioned correctly.
Pump, fans and motors lubricated.

Water freezing in a chiller can rupture the
tubes and cause extensive damage to the
system. It would be desirable to charge
the initial amount of refrigerant without
water in the shell and tube equipment to
eliminate the possibility of freeze up.
3.

After some refrigerant has entered the
system, the compressor unit starting procedure may be followed. See Start-Up and
Operation Section of this manual.

Continue charging refrigerant into the
system until the proper operating requirements are satisfied. Then, close the liquid
charging connection and open the liquid
line valve allowing the system to operate
normally. To check that enough refrigerant has been added, the liquid sight glass

Controls

Initial Charging – High Side Charging

There are two methods of charging refrigerant into the system, through the “high side” or
through the “low side”. High side charging is
usually used for initial charging as filling of the

High side charging of refrigerant into the system
is accomplished as follows:

Low Side Equipment

Controls should be at the initial set points. See
microprocessor manual for further information.
E.

system is much faster. Low side charging is
usually reserved for adding only small amounts
of refrigerant after the system is in operation.

Installation

should show no bubbles, and there will be a
liquid seal in the receiver. If these two conditions are not satisfied, additional refrigerant
must be added.
5.

When sufficient refrigerant has been
charged into the system, close the charging
and drum valves. Then remove the drum
from the system.

During the charging period, observe the
gauge carefully to insure no operating difficulties. Watch head pressures closely to
make sure the condensers are functioning
properly.

Since it is usually necessary to use several drums
when charging a system, follow the procedures
in paragraphs E1 and E2 of the above description
when attaching a new drum. After charging,
the refrigerant drums should be kept nearby for
several days as it is sometimes necessary to add
more refrigerant as the system “settles down”.
VIII.

MAINTENANCE SUGGESTIONS

Careful checking of a refrigeration system for
leaks and proper operation of all components
upon installation will start the system on its way
to a long life of satisfactory service. To ensure
the desired trouble-free operation, however, a
systematic maintenance program is a prerequisite. The following maintenance schedule is
suggested.
A.

Daily

Check oil levels.

Check all pressure and temperature readings.

Check micronic oil filter inlet and outlet pressures for excessive pressure drop. Change
filter when pressure drop exceeds 45 psi or
every six months, whichever occurs first. For
proper procedure for changing micronic oil
filter and for charging oil into the system, see
Operation Section.

Clean strainers each time filter cartridge
if replaced.

Check compressor sound for abnormal
noises.

Check shaft seals for excessive oil leakage.
A small amount of oil leakage (approximately 10 drops/min) is normal. This
allows lubrication of the seal faces.

Weekly
(Items 1 thru 6 above plus 7 thru 9)

Check the refrigeration system for leaks
with a suitable leak detector.

Check oil pressures and review microprocessor log and log sheets.

Check refrigerant levels in vessels.

Monthly
(Items 1 thru 8 above plus 9 thru 13)

10. Oil all motors and bearings. Follow manufacturer’s instructions on lubrication.
11. Check calibration and operation of all
controls, particularly safety controls.
12. Check oil cooler for any evidence of corrosion, scaling or other fouling.
13. Operate compressor capacity and volume
ratio controls through their range both
automatically and manually.
D.

Trimonthly
(About 2000 operating hours)

Check movement of compressor rotor at drive
coupling end to determine bearing float. (Refer to Service Section.)
E.

Yearly
(Items 1 thru 13 and “D” above plus 14
thru 28)

14. Check entire system thoroughly for leaks.

Installation

17. Clean all oil strainers.

tightened, all plugs that were removed are replaced with a suitable thread filling compound,
all packing glands on valve stems are tightened,
and all valve caps are replaced. When operation
is restored, all joints opened or any valves moved
during the servicing should be checked for leaks.

18. Clean suction strainer – compressors.

19. Check motors and fans for shaft wear and
end play.

On a continual basis:

15. Remove all rust from equipment, clean and
paint.
16. Flush out sediment, etc. from water circuits.

20. Check operation and general condition of
microprocessor and other electrical controls.
21. Clean all water strainers.
22. Check drains to make sure water will flow
away from equipment.
23. Drain and clean entire oil system at receiver
drain. Recharge with new clean moisture
free oil. For proper procedure for changing
micronic oil filter and charging oil into the
system, see Start-Up and Operation section.
24. Check compressor coupling. For integrity
and alignment.
25. Check oil pump for wear.
26. Check the calibration of the microprocessor
pressure transducers and RTD’s for accuracy.
27. Check mounting bolts for compressor and
motor.
F.

System Leaks

There are any number of reasons why leaks
develop in a refrigeration system (i.e. such as
drying out of valve packing, yielding of gaskets,
improper replacement of valve caps and loosening of joints due to vibration). For these reasons,
the need for periodic leak testing cannot be overemphasized. Similarly, when any service operations are performed on the system, care should
be exercised to insure all opened flanges are

Year Round Operation

Guard against liquid slugging of compressor.

Maintain unit in clean condition and paint
as necessary.

Grease valve stems and threads for the
valve caps.

When refrigeration equipment is operated 24
hours a day year round, it is highly recommended that a yearly check of all internal parts be
made (see Service Section). While the highest
material standards are maintained throughout
all Vilter compressors, continuous operation
and any presence of dirt may prove injurious to
the machine. To forestall needless shutdowns
or prevent possible machine breakdowns, the
side covers should be removed yearly, and a
visual inspection be made of the internal parts.
In this way, a small amount of time spent checking machine conditions once a year may prevent
extensive shutdowns later with subsequent
product loss and expensive repairs.

Stop Check Valve Installation

Correct

Wrong

Verify the location of the Spring and note the Vilter name.

Installation:
The new design will apply only to the 2” thru 4” stop valves. Retrofitting a field installation will
require replacing the bonnet assembly.
The bonnet must be installed with the spring towards the bottom (see illustrations above).
The drill fixture is designed so that the hole for the spring will always be drilled on the opposite side from the cast-in Vilter name on the bonnet. From the outside of the valve, the casting
numbers must always be towards the top of the valve.
See Operation Section on Stop Check Operation.

Coupling Installation

B. Straight Bore:
1. Install key(s) in the shaft. If the hub is an interference fit, heat the hub in an oil bath or oven until
bore is sufficiently larger than the shaft. 350º F.
is usually sufficient. An open flame is not recommended. However, if flame heating is necessary,
use a very large rose bud tip to give even heat
distribution. A thermal heat stick will help determine hub temperature. DO NOT SPOT HEAT THE
HUB OR DISTORTION MAY OCCUR. With the hubs
expanded, slide it up the shaft to the desired axial
position. A pre-set axial stop device can be helpful.
C. Taper Bore:

COUPLING INFORMATION
COUPLINGS INSTALLATION AND ALIGNMENT
These instructions are intended to help you to install
and align the coupling. Covered here will be general
information, hub mounting, alignment, assembly,
locknut torquing, discpack replacement, and part
numbers. The coupling as received, may or may not
be assembled.
*If assembled, the locknuts are not torqued.
*If coupling is assembled, remove the bolts that attach the hubs to the disc packs. Remove both hubs.
Leave the disc packs attached to the center member.
A. Hub Mounting:
1. Clean hub bores and shafts. Remove any nicks
or burrs. If bore is tapered, check for good contact
pattern. If the bore is straight, measure the bore
and shaft diameters to assure proper fit. The key(s)
should have a snug side-to-side fit with a small
clearance over the top.
NOTE: If the hub position on the shaft does not allow
enough room to install the short bolts in the hub after
hub mounting, install the bolts and disc pack before
mounting hub on shaft.

1. Put the hub on the shaft without key(s) in place.
Lightly tap hub up the shaft with a soft hammer.
This will assure a metal-to-metal fit between shaft
and hub. This is the starting point for the axial
draw. Record this position between shaft and hub
face with a depth micrometer. Mount a dial indicator to read axial hub movement. Set the indicator
to “0”. Remove hub and install key(s). Remount
hub, drawing it up the shaft to the “0” set point.
Continue to advance hub up the taper to the desired axial position. Use the indicator as a guide
only. A pre-set axial stop device can be helpful.
Check the final results with a depth micrometer.
The hub may have to be heated in order to reach
the desired position on the shaft. DO NOT SPOT
HEAT THE HUB OR DISTORTION MAY OCCUR.
Install shaft locknut to hold hub in place.
D. Shaft Alignment.
Move equipment into place.
1. Soft Foot. The equipment must sit flat on its
base (+/- 0.002 inches). Any soft foot must be
corrected now.
2. Axial Spacing. The axial spacing of the shafts
should be positioned so that the disc packs (flexing elements) are flat when the equipment is
running under normal operating conditions. This
means there is a minimal amount of waviness in
the disc pack when viewed from the side. This

Installation

will result in a flexing element that is centered and
parallel to its mating flange faces. Move the connected equipment to accomplish the above.

Note: Alignment of C-Flange Units should be
checked when compressor or motor are replaced.

NOTE: The disc pack is designed to an optimal thickness and is not to be used for axial adjustments.
See documentation that came with the coupling for
complete specifications.
3. Angular Alignment. Rigidly mount a dial indicator
on one hub or shaft, reading the face of the other
hub flange, as shown on next page. Rotate both
shafts together, making sure the shaft axial spacing
remains constant. Adjust the equipment by shimming and/or moving so that the indicator reading
is within .002 inch per inch of coupling flange.
4. Parallel Offset. Rigidly mount a dial indicator on
one hub or shaft, reading the other hub flange outside diameter, as shown in Figure 3. Indicator set-up
sag must be compensated for. Rotate both shafts
together. Adjust the equipment by shimming and/
or moving so that the indicator reading is within
.002 inch per inch of the axial length between flex
elements. See drawing below.
Note: If the driver or driven equipment alignment
specification is tighter than these recommendations,
the specification should be used. Also, be sure to
compensate for thermal movement in the equipment.
The coupling is capable of approximately four time
the above shaft alignment tolerances. However, close
alignment at installation will provide longer service
with smoother operation.
E. Final assembly
With the coupling in good alignment the bolts will fit
through the holes in the flanges and the disc packs
more easily.
1. If the coupling arrived assembled, the disc packs
are still attached to the center ring. Before tak-

ing the discs packs off, first install one hub bolt
through each disc pack and secure with lock out.
This will help when the pack is reinstalled late. If
the coupling was shipped disassembled, the bolt
through the pack is not required as the discs in the
pack are factory taped together.
2. Remove the long bolts. Mount the disc packs
on the hubs with one bolt through the disc pack
aligned with a clearance hole in the hub. Install
the short bolts through the hub, disc pack, bevel
washer or link, and secure with a lockout.
NOTE: All bolt threads should be lubricated. A clean
motor oil is recommended. On size 226 and larger, a
link must be put on bolt first. Remove the disc pack
alignment bolt. Proceed to mount the second disc
pack to the other hub in the same way.
3. Position one set of short bolts in each hub on
top. Now slide the center ring down into place
straddling the short bolts with the center ring
bushings. If coupling is dynamically balanced, the
center ring match marks must lineup with both
hub match marks. When one bushing is in-line
with the hole in the disc pack, slide one long bolt
through washer or link, disc pack, center ring,
disc pack, washer or link, and then secure with a
locknut. On size 226 and larger a link must be put
on the bolt first. Now install the rest of the long
bolts in the same manner.

Installation

4. Torque the long bolt locknuts at this time.
NOTE: With the coupling in good alignment, the bolts
will fit through the holes in the flanges and the disc
pack more easily. It is recommended that all locknuts
be retightened after several hours of initial operation.
5. For further help with the installation or alignment, consult Rexnord.
F. Disc Pack Replacement.
If it becomes necessary to replace the disc pack, it can
be done as follows:
1. Remove all the long bolts and lower the center
ring by sliding it our from between the two disc
packs.
2. Remove one short bolt from the disc pack/hub
connection and reinstall it through a hub clearance
hole and into the hole in the disc pack. Put the nut
on. This will keep the discs together and maintains
the disc orientation for later reinstallation. Remove
the rest of the short bolts and takeoff the disc pack.
Repeat for the second disc pack.
3. Replace the pack(s) if required. Recheck alignment per Section D. Reassemble per Section E.

Slide Valve Actuator Installation & Calibration

Slide Valve Actuator Installations Instructions

Caution
WHEN INSTALLING THE OPTICAL SLIDE MOTOR,
LOOSEN LOCKING COLLAR BEFORE SLIDING THE
COLLAR DOWN ON THE SHAFT. DO NOT USE A
SCREWDRIVER TO PRY LOCKING COLLAR INTO
POSITION.
OVERVIEW
Calibration of an optical slide valve actuator is a two
step process that must be done for each actuator
installed of the compressor. Briefly, the steps are as
follows.
1) The actuator motor control module, located
inside the actuator housing, is calibrated so
that it knows the minimum and maximum rotational positions of the slide valve it controls.
The calibrated actuator will output 0 VDC at the
minimum position and 5 VDC at the maximum
position.
2) After the actuator motor control module has been
calibrated for 0-5Volts, the controlling channel
corresponding to the actuator motor (either the
capacity or volume) has to be calibrated. This
instructs the control panel to learn the rotational
0% position & rotational 100% position of the slide
valve travel.
PLEASE NOTE:
Because there is an optical sensor on this motor, do
not attempt calibration in direct sunlight.

ACTUATOR MOTOR CONTROL
MODULE CALIBRATION PROCEDURE
1.

Disable the Slide Non-Movement Alarm by
going to the “Setup” menu on the control
panel and choosing “Alarm Disable” for the
Slide Non-Movement Option. (If applicable).

Completely shut off the power to the control
panel completely.

If not already done, mount the slide valve
actuator per (“Vilter Actuator set up for
Capacity and Volume Slide Motors). Next,
wire the actuator per the attached wiring
diagrams, using the already installed electrical conduit to run the cables. The old wiring
can be used to pull the new cables through
the conduit to the control panel. The cables
may also be externally tie-wrapped to the
conduit. Run the yellow AC power cable(s)
and the gray DC position transmitter
cable(s) in different conduit. This prevents
the DC position transmitter cable from picking up electrical noise from the AC power
cable. Do not connect either of the cables
to the actuators yet.

In addition, if the actuators are replacing old gearmotors on early units, you must remove the capacitors and associated wiring from inside the control
panel. This is necessary to prevent electrical damage
to the new actuator motor.
4.

When completing the calibration of the
new actuators, the motors are signaled to
move to below 5%. This may not completely
occur when exiting the calibration screen
due to a “program timer”. HOWEVER,
when the compressor actually starts, the
motors will travel below 5% and function
correctly. The user may see that the actuators are not below 5% after calibration and
try to find the reason. If the calibration
screen is re-entered right away and then
exited, the timer will allow the actuator to
go below the 5% on the screen. This may be
perceived as a problem; in reality,it is not.

5. Note:
The 0 to 5V-position transmitter output of
the actuator will fluctuate wildly during the
calibration process. To prevent damage to
the actuators, do not connect the yellow
power cable or the gray position transmitter
cable until instructed to do so later on.
6. Open the plastic cover of the capacity motor by
removing the four #10 screws.

Slide Valve Actuator Installation & Calibration

Caution: there are wires attached to the connector on the plastic cover. Handling the
cover too aggressively could break the wires.
7. Gently lift the cover and tilt it toward the Turck
connectors. Raise the cover enough to be able
to press the blue calibrate button and be able
to see the red LED on the top of assembly.
8. Press “Menu” on the main screen and then press
the “Slide Calibration” button, to enter the slide
calibration screen. (Note: you must be in this slide
calibration screen before attaching the yellow
power cable or gray position transmitter cable.)
9. Now connect the yellow power cable and the
gray position transmitter cable to the actuator.
10. Press INC and DEC to move the slide valve and check
for the correct rotation. See Table 1on page 48 for
Actuator/command shaft rotation specifications.
11. Note: If the increase and decrease buttons do
not correspond to increase or decrease shaft
rotation, swap the blue and brown wires of
the “yellow power cable”. This will reverse
the rotation of the actuator/command shaft.
12. Quickly press and release the blue push button on the actuator one time. This places the actuator in calibration mode. The
r e d L E D w i l l b e g i n f l a s h i n g r a p i d l y.
13. Note: When the actuator is in calibration
mode, it outputs 0V when the actuator is running
and 5V when it is still. Thus, as stated earlier, the
actuator voltage will fluctuate during calibration. After the actuator has been calibrated,
0V output will correspond to the minimum
position and 5V to the maximum position.
14. Note: The “Slide calibration” screen on the control panel has a “Current” window, which displays
twice the actuator output voltage. This value,
(the % volume and the % capacity) displayed in
the “Current Vol” and Current Cap” Windows are
meaningless until calibration has been completed.

15. Use the DEC button on the control panel to
drive the slide valve to its minimum “mechanical stop” position. Do not continue to run the
actuator in this direction after the slide valve
has reached the stop. Doing so may cause damage to the actuator or the slide valve. When
the slide has reached the mechanical stop position, use the INC button to pulse the actuator
to where the slide is just off of the mechanical
stop and there is no tension on the motor shaft.
16. Quickly press and release the blue button on
the actuator again. The red LED will now flash
at a slower rate, indication that the minimum
slide valve position (0V position) has been set.
17. Use the INC button on the control panel to drive
the slide to its maximum “mechanical stop” position. Do not continue to run the actuator in this
direction after the slide valve has reached the
stop. Doing so may cause damage to the actuator or the slide valve. When the slide valve has
reached the mechanical stop position, use the
DEC button to pulse the actuator to where the
slide is just off of its mechanical stop and there
is no tension on the motor shaft.
18. Quickly press and release the blue button on the
actuator one more time. The red LED will stop
flashing. The actuator is now calibrated and knows
the minimum and maximum positions of the slide
valve it controls. Now the capacity or volume
channel of the control panel can be calibrated.
19. Use the Dec button to move the actuator towards
its minimum position while watching the millivolt readout on the control panel screen. Discontinue pressing the DEC button when the millivolt
reading in the “Current” window above the “Set
Min” button is approximately 500 millivolts.
20. Now use the DEC and INC buttons to position the
slide valve until a value close to 300 millivolts is on
the screen. Then, press the “Set Min” button for
the capacity or volume slide valve window to tell
the controller that this is the minimum millivolt
position. Note: The value in the “Current Cap” or
“Current Vol” window has no meaning right now.

Slide Valve Actuator Installation & Calibration

21. Use the INC button to rotate the actuator towards its maximum position while watching
the millivolt readout on the controller screen.
Discontinue pressing the INC button when
the millivolt reading in the “Current” window
is approximately 9200 millivolts (7900 millivolts for the 2783J qualified analog boards).
You are nearing the mechanical stop position.
22. Pulse the INC button to carefully move the slide
valve until the millivolt readout “saturates”, or
stops increasing. This is around 9500 millivolts
(8400 millivolts for 2783 qualified analog boards).
23. Pulse the DEC button until the millivolts just
start to decrease. (This is the point where
the channel drops out of saturation).Adjust millivolt value to 300 millivolts below
recorded maximum millivolts in step #22.
24. Press the “Set Max” button.
25. Press the “Main” button to complete calibration and exit the “Slide Calibration” screen.
The controller will automatically energize
the actuator and drive it back to its minimum position (below 5%) for pre-start-up.
26. Note: Now the “Current Cap” or the “Current
Vol” value will be displayed in the window on the
“Main” screen and the “Slide Calibration” screen.
27. Gently lower the plastic cover over the top
of the actuator to where it contacts the base
and o-ring seal. After making sure the cover
is seated properly, gently tighten the four
#10 screws. Caution: The plastic cover
will crack if the screws are over tightened.
28. Enable the “Slide Non-Movement Alarm” by going to the “Setup” menu and choosing “Alarm
Enable” for the “Slide Non-Movement Option”.
29. This completes the calibration for this channel either capacity or volume. Repeat the
same procedure to the other channel.

Slide Valve Operation

Slide Valve Actuator Operation
The slide valve actuator is a gear-motor with a position sensor. The motor is powered in the forward
and reverse directions from the main computer in
the control panel. The position sensor tells the main
computer the position of the slide valve. The main
computer uses the position and process information
to decide where to move the slide valve next.
The position sensors works by optically counting motor turns. On the shaft of the motor is a small aluminum “photochopper”. It has a 180 degree fence that
passes through the slots of two slotted optocouplers.
The optocouplers have an infrared light emitting diode (LED) on one side of the slot and a phototransistor
on the other. The phototransistor behaves as a light
controlled switch. When the photochopper fence
is blocking the slot, light from the LED is prevented
from reaching the phototransistor and the switch is
open. When photochopper fence is not blocking the
slot, the switch is closed.
As the motor turns, the photochopper fence alternately blocks and opens the optocoupler slots,
generating a sequence that the position sensor microcontroller can use to determine motor position by
counting. Because the motor is connected to the slide
valve by gears, knowing the motor position means
knowing the slide valve position.
During calibration, the position sensor records the
high and low count of motor turns. The operator tells
the position sensor when the actuator is at the high
or low position with the push button. Refer to the
calibration instructions for the detailed calibration
procedure.
The position sensor can get “lost” if the motor is
moved while the position sensor is not powered. To
prevent this, the motor can only be moved electrically
while the position sensor is powered. When the position sensor loses power, power is cut to the motor. A
capacitor stores enough energy to keep the position
sensor circuitry alive long enough for the motor to
come to a complete stop and then save the motor
position to non-volatile EEPROM memory. When
power is restored, the saved motor position is read
from EEPROM memory and the actuators resumes
normal function

This scheme is not foolproof. If the motor is moved
manually while the power is off or the motor brake
has failed, allowing the motor to free wheel for too
long after the position sensor looses power, the actuator will become lost.
A brake failure can sometimes be detected by the
position sensor. If the motor never stops turning after
a power loss, the position sensor detects this, knows
it will be lost, and goes immediately into calibrate
mode when power is restored.

Slide Valve Actuator Trouble Shooting Guide
Problem
The actuator cannot be calibrated

Reason
Dirt or debris is blocking one or
both optocoupler slots

Clean the optocoupler slots
with a Q-Tip and rubbing alcohol.

The photochopper fence extends
less than about half way into the
optocoupler slots

Adjust the photochopper so
that the fence extends further
into the optocoupler slots.
Make sure the motor brake
operates freely and the photochopper will not contact the
optocouplers when the shaft is
pressed down.

The white calibrate wire in the grey
Turck cable is grounded
Dirt and/or condensation on the
position sensor boards are causing
it to malfunction

The actuator goes into calibration mode spontaneously

Tape the end of the white wire
in the panel and make sure that
it cannot touch metal
Clean the boards with an electronics cleaner or compressed
air.

The calibrate button is stuck
down

Try to free the stuck button.

The position sensor has failed

Replace the actuator.

Push button is being held down for
more that ¾ second when going
through the calibration procedure

Depress the button quickly and
then let go. Each ¾ second the
button is held down counts as
another press.

The white calibrate wire in the grey
Turck cable is grounding intermittently

Tape the end of the white wire
in the panel and make sure that
it cannot touch metal.

A very strong source of electromagnetic interference (EMI), such as a
contactor, is in the vicinity of the
actuator or grey cable

Increase the distance between
the EMI source and the actuator.

There is an intermittent failure of
the position sensor

The actuator goes into calibration mode every time
power is restored after a
power loss

Solution

Install additional metal shielding material between the EMI
source and the actuator or
cable.
Replace the actuator.

The motor brake is not working properly (see theory section
above.)

Get the motor brake to where it
operates freely and recalibrate.
Replace the actuator.

Slide Valve Actuator Trouble Shooting Guide
Problem
The actuator does not transmit the correct position after
a power loss

Reason
The motor was manually moved
while the position sensor was not
powered.
The motor brake is not working
properly

There is a rapid clicking noise
when the motor is operating

The motor operates in one
direction only

The motor will not move in
either direction

The motor runs intermittently,
several minutes on, several
minutes off

Solution
Recalibrate.
Get the motor brake to where it
operates freely and then recalibrate.

The position sensor’s EEPROM
memory has failed

Replace the actuator.

The photochopper is misaligned
with the slotted optocouplers

Try to realign or replace the actuator.

The photochopper is positioned
too low on the motor shaft.

Adjust the photochopper so that
the fence extends further into
the optocoupler slots.

A motor bearing has failed

Replace the actuator.

There is a loose connection in the
screw terminal blocks

Tighten.

There is a loose or dirty connection in the yellow Turck cable

Clean and tighten.

The position sensor has failed

Replace the actuator.

There is a broken motor lead or
winding

Replace the actuator.

The thermal switch has tripped
because the motor is overheated

The motor will resume operation when it cools. This could be
caused by a malfunctioning control panel. Consult the factory.

Any of the reasons listed in “The
motor operates in one direction
only”

See above.

The command shaft is jammed

Free the command shaft.

Broken gears in the gearmotor

Replace the actuator.

Motor is overheating and the
thermal switch is tripping

This could be caused by a malfunctioning control panel. Consult the factory.

Slide Valve Actuator Trouble Shooting Guide
Problem

Reason

The motor runs sporadically

The motor runs but output
shaft will not turn

Solution

Bad thermal switch

Replace the actuator.

Any of the reasons listed in “The
motor will not move in either direction”

See above.

Stripped gears inside the gear motor or the armature has come unpressed from the armature shaft

Replace the actuator.

Slide Valve Actuators communicate problems discovered by internal diagnostics via LED blink codes. Only one blink
code is displayed, even though it is possible that more than one problem has been detected.

Flash Pattern

Meaning

*=ON
_=OFF
*_*_*_*_*_*_*_*_*_*_*_

Calibration step 1

*___*___*___*___*___

Calibration step 2

*__*________________

This indicates a zero span. This error can only occur during calibration. The typical
cause is forgetting to move the actuator when setting the upper limit of the span.
If this is the case, press the blue button to restart the calibration procedure. This
error can also occur if either or both of the slotted optocouplers are not working. If
this is the case, the slide valve actuator will have to be replaced.
The operation of the slotted optocouplers is tested as follows:
1. Manually rotate the motor shaft until the aluminum photochopper fence is not
blocking either of the optocoupler slots.
2. Using a digital multi-meter, measure the DC voltage between terminal 3 of
the small terminal block and TP1 on the circuit board (see Note 1). You should
measure between 0.1 and 0.2 Volts.
3. Next, measure the DC voltage between terminal 3 and TP2 on the circuit
board. You should measure between 0.1 and 0.2 Volts.

Slide Valve Actuator Trouble Shooting Guide

*__________________

This indicates a skipped state in the patterns generated by the optocouplers as the
motor moves. This error means that the slide valve actuator is no longer transmitting accurate position information. The actuator should be recalibrated as soon as
possible. This code will not clear until the actuator is recalibrated.
This code can be caused by:
1. The motor speed exceeding the position sensors ability to measure it at some
time during operation. A non-functioning motor brake is usually to blame.
2. The actuator is being operated where strong infrared light can falsely trigger
the slotted optocouplers, such as direct sunlight. Shade the actuator when the
cover is off for service and calibration. Do not operate the actuator with the
cover off.

*__*__*____________

The motor has overheated. The actuator motor will not run until it cools. Once the
motor cools, the actuator will resume normal operation.
Motor overheating is sometimes a problem in hot and humid environments when
process conditions demand that the slide valve reposition often. Solutions are
available; consult your Vilter authorized distributor for details.
Another possible cause for this error is a stuck motor thermal switch. The thermal switch can be tested by measuring the DC voltage with a digital multi-meter
between the two TS1 wire pads (see Note 2). If the switch is closed (normal operation) you will measure 0 Volts.

********************

The 24V supply is voltage is low. This will occur momentarily when the actuator is
powered up and on power down.
If the problem persists, measure the voltage using a digital multi-meter between
terminals 3 and 4 of the small terminal block. If the voltage is >= 24V, replace the
actuator.

_*******************

The EEPROM data is bad. This is usually caused by loss of 24V power before the
calibration procedure was completed. The actuator will not move while this error
code is displayed. To clear the error, calibrate the actuator. If this error has occurred and the cause was not the loss of 24V power during calibration, possible
causes are:
1. The EEPROM memory in the micro-controller is bad.
2. The large blue capacitor is bad or has a cracked lead.

*****____*__________

Micro-controller program failure. Replace the actuator.

Note 1: TP1 and TP2 are plated-thru holes located close to the slotted optocouplers on the board. They are clearly
marked on the board silkscreen legend.
Note 2: The TS1 wire pads are where the motor thermal switch leads solder into the circuit board. They are clearly
marked on the board silkscreen legend and are oriented at a 45 degree angle.

Operation Section

Notice on using Non -Vilter Oils

Oil and its additives are crucial in system performance. Vilter Manufacturing will NOT APPROVE non-Vilter oils
for use with Vilter compressors. Due to the innumerable choices available it is not possible for us to test all oils
offered in the market place, and their effects on our equipment.
We realize that customers may choose lubricants other than Vilter branded oil. This is certainly within the
customers’ right as owners of the equipment. When this choice is made, however, Vilter is unable to accept
responsibility for any detrimental affects those lubricants may have on the equipment or system performance
and durability.
Should a lubrication related system issue occur with the use of non-Vilter oils, Vilter may deny warranty upon
evaluation of the issue. This includes any parts’ failure caused by inadequate lubrication.
Certainly, there are many good lubricants in the market place. The choice of a lubricant for a particular application involves consideration of many aspects of the lubricant and how it and its additive package will
react in the various parts of the entire system. It is a complex choice that depends on a combination of field
experience, lab and field-testing, and knowledge of lubricant chosen. Vilter will not accept those risks other
than for our own lubricants.

Operation

OIL SYSTEM
A. Oil Charge
Charge the oil separator with the proper quantity of
lubricating oil (see Table 2 in the Installation Section).
CAUTION
It is imperative you charge the oil into the receiver/
separator prior to energizing the control panel to
prevent burning out the immersion heater in the
separator/receiver.
During operation, maintain the separator oil level
in the normal operating range between the two
bullseye sight glasses. If the oil level is visible only
in the lowest sight glass, add oil to the operating
compressor through the connection located at the
compressor suction inlet. Pump oil into the compressor until the oil level in the separator is between the
two bullseye sight glasses. Watch this level carefully
to maintain proper operation. Never allow the oil to
reach a level higher than indicated on the highest
sight glass, since this may impair the operation and
efficiency of the oil separator portion of this combination vessel.
B. Oil Separator
The refrigerant-oil mixture is led into the first part
of oil separator. There, the first step of oil separation is performed by a combined agglomerator/
demister. At the same time, these part of the oil
separator serves as oil collector.

To prepare for the removal of the filter, shut down
the compressor. Isolate the filter housing appropriately. If unit is equipped with duplex filter housings
the unit does not have to be shut down, however
the filter to be serviced must be isolated before the
tank can be opened.
1. Filter Removal, VSS Units using Vilter Part
Number 1833C oil filter elements.
Release the pressure in the oil filter housing by
opening the bleed valves at the stop valve in the
block and bleed assembly, or at the bleed valve
for the oil filter housing. Be sure to follow all
Local, State, and Federal ordinances regarding
the recovery of refrigerants.
Drain the filter housing in to an appropriate
container and dispose of the oil in a appropriate
manner following all Local, State and Federal
ordinances regarding the disposal of used oil.
Unscrew the bolts holding the cover flange to
the tank. Remove the cover flange and spring
plate. Pull out the filter element(s). Before
reassembling, thoroughly clean the tank and
spring plate to lengthen the life span of the filter
element(s).

In the second part of the oil separator, the fine
separation of the aerosol oil portion from the refrigerant is performed by means of replaceable fine
oil separation cartridges. The oil separated in the
fine section of the oil separator is returned to the
compressor via an additional injection orifice.
C. Oil Filter
Change the oil filter after the first 200 hours of operation, as noted on the hour meter. Thereafter, replace
the filter every six months, or when the oil pressure
drop through the filter reaches 45 psi, whichever occurs first. The pressure drop across the filter is read
on the microprocessor panel. Check the pressure
drop and record it daily.

1833C
Filter
Element

FIGURE 1.
1833C FILTER ELEMENT TANKS

Operation

Loosen and remove the locking ring on filter
tank by turning in a counter clockwise direction. Remove filter tank with the used element.

To replace the filter element(s), on single element tanks, insert the element and make sure
it fits onto the outlet connection. Install spring
plate, and bolt the cover assembly in place. On
units equipped with dual element tanks, insert
inner element and make sure it fits onto the outlet connection. Put the centering piece on the
outer element and slide into tank making sure
the center piece fits into the inner element. Put
spring plate on outer element and bolt the cover
assembly in place.
2.

Filter Removal and installation, all
VSR Units.
Release the pressure in the oil filter housing by
opening the bleed valves at the stop valve in the
block and bleed assembly, or at the bleed valve
for the oil filter housing. Be sure to follow all Local, State and Federal ordinances regarding the
recovery of refrigerants.

FILTER
TANK

LOCKING
RING

FILTER
ELEMENT

OUTLET

INLET

FIGURE 2.
TYPICAL CANISTER TYPE FILTER CROSS SECTION
Drain the filter bowl or housing in to an appropriate container and dispose of the oil in a appropriate manner following all Local, State and
Federal ordinances regarding the disposal of used
refrigeration oil.

Remove the filter element from the tank. Before reassembling, thoroughly clean the tank
to lengthen the life span of the filter element.
Wet the threads and O-ring on the head and
the O-ring in the new element with clean refrigeration oil.
CAUTION
Do not use a pipe wrench, hammer or any other tool
to tighten the locking ring.
nsert new element into the filter tank with
the open end visible. Attach tank to head and
HAND TIGHTEN the locking ring.
The filter housing can be evacuated and then
slowly pressurized to check for leaks before
returning to service.
3.

Filter Removal, VSS and VSM Units
(after 5/1/00) when using Vilter Part
Numbers 3111A (16” Simplex), or
3112A (39” Simplex) oil filter
housings.
Release the pressure in the oil filter housing by
opening the bleed valves at the stop valve in
the block and bleed assembly, or at the bleed
valve for the oil filter housing. Be sure to follow
all Local, State and Federal ordinances regarding the recovery of refrigerants.
Drain the filter bowl or housing in to an appropriate container and dispose of the oil in a
appropriate manner following all Local, State
and Federal ordinances regarding the disposal
of used refrigeration oil.
Loosen and remove the cover on the bowl of
the filter tank by turning it in a counter clockwise direction. Remove the used element.

Operation

Wet the O-ring in the new element with clean
refrigeration oil. Insert the new element into the
filter tank with the closed end visible and attach
the cover to the bowl. HAND TIGHTEN the cover.
The filter housing can be evacuated and then
slowly pressurized to check for leaks before returning to service.
4.

Filter Removal, VSS and VSM Units (after
5/1/00) when using Vilter Part Numbers
3109A (16” Duplex), or 3110A (39” Du
plex) oil filter housings.
Isolate the bowl to be worked on by turning
handle. The handle will cover the drain valve of
active element. Close commuter valve in center of
handle. Release the pressure in the isolated bowl
by bleeding through the stop valve on the oil filter
cover for Duplex (Vilter Part #3109A or 3110A),
or through the stop valve for the oil filter housing. Be sure to follow all Local, State and Federal
ordinances regarding the recovery of refrigerants.
Drain the filter bowl or housing in to an appropriate container and dispose of the oil in a appropriate manner following all Local, State and
Federal ordinances regarding the disposal of used
refrigeration oil.
Loosen and remove the cover on the bowl of the
filter tank by turning it in a counter clockwise
direction. Remove the used element.
Wet the O-ring in the new element with clean
refrigeration oil. Insert the new element into the
filter tank with the close end visible and attach
the cover to the bowl. HAND TIGHTEN the cover.
The filter housing can be evacuated and then
slowly pressurized by opening the commuter
valve on handle. This will pressurize the housing.
Check for leaks. The filter can now be returned
to service. Repeat for other filter bowl if needed.

CAUTION
When changing filter, discard clogged filter only.
Save and reuse spring plate and centering piece.
This filter MUST be installed with the spring plate.
A compressor that is allowed to operate without
the spring plate is running with unfiltered oil.
The filter housing can be evacuated and then
slowly pressurized to check for leaks before
returning to service.
D. Oil Pressure Regulating
On units with a full time oil pump, the back pressure regulator, in the oil supply line from the separator, controls upstream pressure to the compressor bearings and should be adjusted to hold the oil
pressure at 50 psig above suction pressure. Excess
oil not required for bearing lubrication is passed
through the regulator and flows into the separator.
E. Oil Cooling
1. Water Cooled Oil Cooler
In lieu of the three way oil temperature valve
to control the temperature of the oil used for
lubrication and cooling of the compressor, it is
required to install a water regulating valve and
solenoid valve combination to control the water
supply to the oil cooler. The water inlet connection should be made on the bottom and the
outlet connection on the top. The water supply
is controlled by the water regulating valve to
maintain the oil temperature at approximately
120°F.

Operation

FIGURE 3.
TYPICAL WATER COOLED OIL COOLER
DIAGRAM
The solenoid valve provides positive water shutoff when the compressor is not in operation. A
temperature of 150°F is considered high in most
circumstances and the compressor is protected by
a safety control to prevent operation of the compressor above this temperature. Unless otherwise
specified, the oil cooler is sized for an 85°F water
inlet temperature and 10°F temperature rise.
2. Liquid Injection Oil Cooling.
The components are furnished with liquid injection for a typical system. The liquid solenoid valve
opens whenever the compressor is in operation.
The thermostatic expansion valve controls the
flow of liquid refrigerant to the compressor injection port in response to the discharge temperature. The discharge temperature is maintained at a
minimum of 120°F with a maximum of 140°F. The
discharge temperature can be adjusted either of
two ways. First, the small outlet pressure regulator can be used to adjust superheat. Normally, this
regulator should be adjusted to maintain 70 psig
pressure at the external equalizing port of the expansion valve. Raising the pressure beyond 70 psig
tends to raise the discharge temperature, while
lowering the pressure lowers the discharge temperature. Secondly, the standard superheat adjusting screw on the thermostatic expansion valve can
be used to adjust the discharge temperature.

FIGURE 4.
TYPICAL LIQUID INJECTION OIL COOLING
SCHEMATIC DIAGRAM
Liquid injection cooling on booster compressors
is handled in the following manner. Using high
pressure liquid, the point of injection can be the
discharge line and no horsepower penalty is paid
by injecting liquid into the compressor discharge
line. The high pressure gas source normally used
for the pressure regulator would be compressor
discharge pressure. Since, on a booster unit, this
intermediate pressure is very rarely as high as the
nominal setting of 70 psig, high stage discharge
gas is used. On high stage compressors, the liquid
is injected directly into the compressor. However,
there is a horsepower penalty when the liquid is
injected into the compressor. This will vary with
refrigerant and operating condition. The liquid
is injected into the compressor at a point in the
compressor cycle that minimizes the brake horsepower penalty.
3. V-PLUS Oil Cooling System
This system consists of a liquid pump, shut-off
valves, motor, solid state variable speed controller
and solid state temperature controller. This method of oil cooling is not available on the VSM or VSR
compressor units. The pump and solenoid valve
cycle on and off in parallel with the compressor
drive motor. The temperature controller receives a
temperature signal from the sensor located in the
discharge and oil lines and in turn, sends a signal
to the motor speed controller.

Operation

As the oil and desupserheating load varies, the
temperature controller adjusts the speed of the
pump/motor combination to maintain a constant
oil temperature.
NOTE:
See separate V-PLUS® instruction manual for detailed start-up and operation.
4. Thermosyphon Oil Cooling
Using a brazed plate or an one pass shell and tube
type vessel, similar to the water cooled oil cooler,
oil is circulated on the shell side and liquid refrigerant from the receiver is circulated through
the tubes. Thermosyphon systems use a 3-way
temperature sensing control valve to regulate oil
at 120°F. Oil is bypassed around the thermosyphon
oil cooler. When oil is higher than 120°F, the oil is
passed through the thermosyphon oil cooler. A
1/4” tubing line w/valve adds high pressure gas to
the oil to quiet the sound of injection. Open this
valve in small amounts, until noise subsides. The
closed type cooling circuit is free from the fouling problems associated with open circuit water
cooling. Since the oil cooling load is rejected in
the condenser, this type of cooling is practical.
The temperature limits here are the same as those
regarding the water cooled oil coolers.
5. Oil Pump
This system is designed to provide adequate compressor lubrication when there is low differential
oil pressure across the compressor suction and
discharge for some high stage applications and
booster applications as required.
On start-up, the control system will calculate the
pressure differential between the compressor oil
manifold & suction pressure. If this differential
pressure ratio is less than 2.8:1, then the oil pump
will turn on and will continue to run until the pressure ratio is 3.0:1.

CONTROL SYSTEM
Equipped for automatic operation, the screw compressor unit has safety controls to protect it from
irregular operating conditions, an automatic starting and stopping sequence, capacity and volume
ratio control systems.
Check all pressure controls with a remote pressure source, to assure that all safety and operating
control limits operate at the point indicated on the
microprocessor.
The unit is equipped with block and bleed valves
that are used to recalibrate the pressure transducers. To use the block and bleed valves to recalibrate
the pressure transducers, the block valve is shut
off at the unit and the pressure is allowed to bleed
off by opening the bleed valve near the pressure
transducer enclosure. The transducer can then be
calibrated at atmospheric pressure (0 psig), or an
external pressure source with an accurate gauge
may be attached at the bleed valve.
The discharge pressure transducer cannot be isolated from its pressure source, so it is equipped with
only a valve to allow an accurate pressure gauge to
be attached and the pressure transducer calibrated
at unit pressure.
Recheck the transducers periodically for any drift
of calibration.
A. Screw Compressor Control And Operation
1. Starting, Stopping and Restarting the Compressor.
Before the screw compressor unit is started,
certain conditions must be met. All of the
safety setpoints must be in a normal condition,
and the suction pressure must be above the
low suction pressure setpoint to assure that a
load is present. When the “On-Off” switch or

Operation

“Manual-Auto” button is pressed, the oil pump
will start. When sufficient oil pressure is built
up and the compressor capacity control and
volume ratio slide valves are at or below 10%,
the compressor unit will start.
If the compressor is in the automatic mode, it
will now load and unload and vary the volume
ratio in response to the system demands.
Stopping the compressor unit can be accomplished a number of ways. Any of the safety
setpoints will stop the compressor unit if an
abnormal operating condition exists. The compressor unit “On-Off” or stop button will turn
the compressor unit off as will the low pressure
setpoint. If any of these conditions turns the
compressor unit off, the slide valve motors will
immediately energize to drive the slide valves
back to 5% limit. The control motors will be
de-energized when the respective slide valve
moves back below 5%. If there is a power failure,
the compressor unit will stop. If the manual
start on power failure option is selected (see appropriate Microprocessor Instruction Manual),
restarting from this condition is accomplished
by pushing the reset button to insure positive
operator control. If the auto start on power failure option is selected (see appropriate Microprocessor Instruction Manual), the compressor
unit will start up after a waiting period. With
both options, the compressor slide valves must
return below their respective 5% limits before
the compressor unit can be restarted.
2. Slide Valve Control Actuators
Capacity and volume ratio control of the screw
compressor is achieved by movement of the
respective slide valves, actuated by electric
motors.

Note:
Optical Actuators CAN NOT
be manually rotated.
(The VSM 501-701 models
will have motor locations
opposite of figure #6)

FIGURE 5.
SLIDE VALVE MOTOR LOCATION
When viewing the compressor from the discharge end (opposite the drive end), the upper
motor is for capacity control. The command
shaft turns (see Table 1) to decrease the capacity to 10% and reverses to increase the capacity
to 100%. The lower motor is for volume ratio
control. The command shaft turns to reduce the
volume ratio to 2.0, and reverses to increase the
volume ratio to 5.0.
Actuation of the electric motors can be done
manually or automatically. To actuate the motors manually, place the desired mode selector
in the manual position and push the manual
Increase or Decrease buttons. In the automatic
mode, the microprocessor determines the direction to actuate the electric motors. However,
in the automatic mode, there is an “On” and
“Off” time for the capacity control motor. The
“On” time is the time in which the slide valve
moves, and the “Off” time is the time in which
the system is allowed to stabilize before another
change in slide valve position.

Operation

The Motor Amps Load Limit protects the compressor from overloading by decreasing the
compressor capacity if the motor amperage is
at the Maximum Amps setpoint, or preventing
an increase in capacity if the motor amperage is
above the Full Load Amps setpoint. ( See manual
for the appropriate microprocessor.)

A detailed explanation of all safety setpoints can be
found in the Compact Logix PLC manual, p/n 35391CL.
1. Oil Pressure
Low oil pressure differential stops the compressor
unit when there is an insufficient difference in pressure between the oil manifold and suction.

3. Oil Separator Heater
The oil separator heater keeps the oil in the
separator from becoming too viscous and helps
keep gas from condensing in the receiver section
of the separator.
The heater is turned on only when the compressor is off. The separator heater is supplied with
an integral temperature control.
TABLE 1.

B. Safety Setpoints

2. Discharge Pressure
High discharge pressure cutout stops the compressor unit, when the discharge pressure in the oil
separator exceeds the setpoint.

VSS / VSR / VSM COMMAND SHAFT ROTATION AND TRAVEL

COMMAND SHAFT ROTATION
NO. OF TURNS / ROTATION ANGLE / SLIDE TRAVEL
COMP.
CAPACITY
VOLUME
CAPACITY
VOLUME
MODEL
INC
DEC
INC
DEC
TURNS/ANGLE/TRAVEL
TURNS/ANGLE/TRAVEL
VSS 291
CW
CCW CW
CCW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSS 341
CW
CCW CW
CCW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSS 451
CW
CCW CW
CCW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSS 601
CW
CCW CW
CCW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSS 751
CCW CW
CCW CW
1.09 / 392 / 4.283”
0.63 / 227 / 2.473”
VSS 901
CCW CW
CCW CW
1.09 / 392 / 4.283”
0.63 / 227 / 2.473”
VSS 791
CCW CW
CCW CW
1.22 / 439 / 4.777”
0.74 / 266 / 2.889”
VSS 891
CCW CW
CCW CW
1.22 / 439 / 4.777”
0.74 / 266 / 2.889”
VSS 1051
CCW CW
CCW CW
1.22 / 439 / 4.777”
0.74 / 266 / 2.889”
VSS 1201
CCW CW
CCW CW
1.22 / 439 / 4.777”
0.74 / 266 / 2.889”
VSS 1301
CCW CW
CCW CW
1.22 / 439 / 4.777”
0.74 / 266 / 2.889”
VSS 1501
CCW CW
CCW CW
1.36 / 490 / 5.325”
0.82 / 295 / 3.200”
VSS 1801
CCW CW
CCW CW
1.36 / 490 / 5.325”
0.82 / 295 / 3.200”
VSM 71
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 91
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 101
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 151
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 181
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 201
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 301
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 361
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 401
CW
CCW CW
CCW
0.80 / 288 / 3.141”
0.45 / 162 / 1.767”
VSM 501
CCW CW
CCW CW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSM 601
CCW CW
CCW CW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
VSM 701
CCW CW
CCW CW
0.91 / 328 / 3.568”
0.52 / 187 / 2.045”
NOTE: These refer to the old style gear motors and DO NOT apply to the new optical motors.Rotation for the
optical motors is the OPPOSITE of what is shown in the chart.

Operation

3. Suction Pressure
Low suction pressure cutout stops the compressor unit when the suction pressure drops below
the setpoint.
4. Oil Filter Differential
High oil filter differential cutout stops the compressor unit when the difference between the
outlet and inlet of the filter exceeds the setpoint.

4. Manually open the oil isolating valve at the oil
separator outlet connection.
5. Open the isolating valve(s) before and after the
oil filter housings.
6. Manually open the stop valve on the oil bleed
return line from the element section and open
the expansion valve 1/2 of a turn.

5. Oil Temperature
The oil temperature cutout stops the compressor unit when the oil temperature is too high
or too low.

STRAINER

CHECK
VALVE
TO COMPRESSOR
SG

SIGHT
GLASS

6. Discharge Temperature
The high discharge temperature cutout stops
the compressor unit when the discharge temperature exceeds the setpoint.

INITIAL START-UP
A. Setting of Controls
(Refer to the appropriate microprocessor manual
for a list of initial settings.)
B. Valve Settings
1. The suction line uses separate stop and check
valves. Ensure the suction stop valve is open
prior to starting.
2. The ¼” suction equalization valve should be
closed during operation. The valve enables the
unit to slowly equalize to low side pressure during off periods. This valve must be adjusted to
minimize oil loss when compressor stops.
3. The discharge line uses separate stop and check
valves. Ensure the discharge valve is open prior
to starting.

HAND EXPANSION
VALVE

FIGURE 6.
OIL SEPARATOR BLEED LINE
NOTE:
The purpose of the oil bleed return assembly is to
collect any oil that passes through the oil separating element and returns that oil to the compressor. The hand expansion valve should be adjusted
to prevent an oil level from forming in the sight
glass when the compressor is at 100% capacity.
Generally 1/2 to 1 turn open is satisfactory.
7.

Open 1/4” high pressure gas line valve piped to
oil injection line just enough to quiet compressor at 100% capacity.

C. Compressor Pre Start-Up Check List
Before proceeding with actual starting of the
compressor, the items listed on the “Pre Start-Up
Check List” must be verified. Time and money will
be saved before the Vilter start-up technician arrives. (See next page.)

Pre Start-Up Checklists
The following checklists are to help prepare the equipment before the Vilter Technician arrives at the
jobsite. Vilter recommends that a Trained Technician go through the following tasks. The operating
Manuals provided by Vilter, can be referenced for any type of questions or special instructions.
Every Refrigeration unit includes a Vilter Start-Up (Confirm on PO). The following tasks are not included
in the Vilter Start-up provided in your equipment purchase. Any tasks below that are done by the Vilter
Technician will take away from the pre-determined time that was provided with the equipment purchase. Vilter suggests that the Vilter Technician’s time be used during the start-up of the System and
not for the below System Preparation.
Note: Each item below MUST be “Checked-Off”, Signed and Returned to the Vilter Service Department.
Failure to do so will “Null & Void” future Warranty considerations.

Field Piping and Mechanical Requirements
NOTE: If start-up service has been purchased, the following items should be completed before the startup technician arrives. This will help save time and money.
1. The unit should be leveled and secured to the mounting pad or floor.
2. The suction and Discharge line must be piped and properly supported, independent of the unit
3. The Discharge Stop/Check Valve is shipped loose and must be installed in a vertical up flow direction or
in a horizontal line with the valve stem pointing upward at a 45° angle. During off periods, refrigerant
can condense in the line downstream of the Discharge Stop/Check Valve. It is recommended the Stop/
Check Valve be located to minimize the quantity of liquid that can accumulate downstream of the valve.
4. A Dual Safety Relief Valve is shipped loose for field installation. A connection is provided on the oil sepa
rator for the relief valve. Refer to ASHRAE/ANSI Standard 15 (Safety Code for Refrigeration) for proper
sizing and installation of Relief Valves and Vent Lines.
5. Piping For Oil Cooling
a) Liquid Injection
An adequate, or dedicated, liquid line is required for the Liquid Injection System. A high pressure
liquid source must be piped to the stop valve at the inlet of the Thermostatic Expansion Valve. On
booster units, an additional 3/8” line must be piped to the regulator from high stage discharge gas flow
or the Thermostatic Expansion Valve.
b) V-PLUS
A high pressure liquid source must be run to the V-PLUS® inlet. Some subcooling is desirable. A
high pressure float must be installed at the inlet of the pump and a 3/8” vent line must be returned to
a suction trap. Refer to the V-PLUS manual for additional information.
c) External Oil Cooler
On thermosyphon oil coolers, the refrigerant lines must be connected to the front head of the oil
cooler. On water cooled oil coolers, the water lines must be connected to the front head of the oil
cooler. Installation of water regulating and solenoid valves are recommended.
6. The oil separator should be provided with oil until the oil level is between the (2) sight glasses. An oil
charging connection is provided on the bottom of the oil separator.
7. The center member of the compressor coupling is shipped loose to help facilitate final field alignment
and allow for motor rotation check. The motor alignment should be within 0.004” total indicator read
ing in all directions.
a) Both the compressor and motor hubs should be checked for concentricity and perpendicularity.
b) The motor should be checked and shimmed for soft foot prior to attempting final alignment.
c) The center section of the coupling should be left out to allow the start-up technician to verify the
final alignment and motor rotations.
8. The unit should be pressure tested, evacuated and a system load should be available at the
time of start-up.

Order #_______________________________Compressor Serial #________________________
53

Field Wiring Requirements
VRS SCREW COMPRESSOR, VSS/VSM SINGLE SCREW COMPRESSOR UNITS
PRESTART-UP CHECKLIST
FIELD WIRING REQUIREMENTS FOR UNITS WITH FACTORY WIRED VISSION® MICROPROCESSORS
NOTE:

If startup service has been purchased, to save time and money, the following items should be completed
before the startup technician arrives.

The unit is pre-wired at the factory. The necessary field wiring connections are described below.
1.

Control power of 115 VAC 50/60 HZ must be wired to the left side terminals of the digital I/O board inside
the ViSSion® cabinet. Line power (L1) is brought in to a 10-amp fuse via the terminal marked “L1” on the
appropriate connector. The neutral (L1A) is brought in and connected to any of the “N” terminals located
on left connectors. Two separate line power feeds for the oil heaters are brought to two additional 10
amp fuses via the terminals marked “L2” and “L3” on the same connector just below the “L1” terminal.
The neutrals for these circuits (L2A and L3A) are also connected to any of the “N” terminals. For units
with V-PLUS® oil cooling, L1 must also be brought to the fuse in the V-PLUS® panel, and L1A must also be
brought to the terminal #2B in the V-PLUS® panel.

An auxiliary contact from the compressor motor starter is required. This isolated contact is connected to
the K-1 input relay using any of the “L” terminals on the strip of connectors, and returned to the terminal
marked “Motor Starter Aux. Safety” at the very top connector.

A dry contact from control relay K-22 must be wired to the compressor motor starter coil. This dry contact
is wired to terminals marked “Compressor Start – N.O. #1A” and “Compressor Start – N.O. #1B”. Control
power for this coil should come from a source, which will be de-energized with the compressor disconnect.

A dry contact from control relay K-19 must be wired to the oil pump motor starter coil. This dry contact
is wired to the two terminals marked “Oil Pump Starter”. Control power for this coil should come from a
source, which will be de-energized with the compressor disconnect.

An auxiliary safety cutout is available to shut down the compressor package using the K-2 input relay. A
dry contact must be supplied and wired to one of the “L” terminals on any of the connectors, and returned
to the terminal marked “Auxiliary #1 Safety” at the top connector. The jumper to the “Auxiliary #1 Safety”
terminal must be removed to use this cutout. The contact, if closed, will allow the compressor to run. If
this contact opens at any time, the compressor will shut down.

Indication of the compressor alarm or shutdown status is also available via two control relays. Relay K-20
is provided for remote trip indication and relay K-21 is provided for remote alarm indication. Each relay
has three terminals available: a common input, a normally open contact, and a normally closed contact.
For both relays, the energized state represents a “trip” or “alarm” condition. Loss of voltage to the relay
coil and the resultant return to normal state indicates “safe” condition.

The current transformer supplied in the compressor motor conduit box should be checked to insure that
the motor leads of one leg are pulled through the transformer. Note that there is a dot on one side of the
current transformer. This dot must face away from the motor. Typically, a wye delta started motor should
have leads 1 and 6 pulled through this transformer for a 6 lead motor. However, this should always be
checked as different motors and starting methods will require different leads to be used.

Order #_______________________________Compressor Serial #________________________
54

Stop Check Valve Operation

AUTO
In the “Auto Position”, the stop valve is
operating as a check valve, allowing flow
in the directions of the arrows.
To set the valve to the automatic position, fully close the valve, and turn the
stem out as indicated by the chart below.

CLOSED
In the manually “Closed Postion”, the
stop check is operating as a conventional
stop valve, not allowing flow in either
direction.

OPEN
In the manually ” Open Position”, with
the valve stem fully back seated, the
valve disc is lifted slightly, allowing flow
in either direction.

Valve Size

1.5”

2”

2.5”

3”

4”

5”

6”

8”

Number of Turns Open
(from closed position)

2.25

2.75

3.25

4.5

3.75

5.75

7.75

Service

GENERAL COMMENTS
When working on the compressor, care must be taken
to ensure that contaminants (i.e. water from melting
ice, dirt and dust) do not enter the compressor while
it is being serviced. It is essential that all dust, oil or
ice that has accumulated on the outside of the compressor be removed before servicing the compressor.
When servicing the compressor, all gaskets, O-rings,
roll pins and lock washers must be replaced when
reassembling the compressor.

A) Disconnect the motor drive coupling from the
compressor input shaft.
B) Disconnect all gas and oil piping which is attached to the compressor. When removing the
suction strainer on gas compression units, the
suction line should be supported to prevent it
from sagging.
C) Replace oil drain in compressor housing and discharge manifold after oil has stopped draining.
D) Remove all electrical connections to the compressor.

PREPARATION OF UNIT FOR SERVICING

E) On compressors with mounting feet, loosen and
remove bolts holding the compressor to the
base.
A) Shut down the unit, open the electrical disconnect switch and pull the fuses for the compressor
motor to prevent the unit from starting. Put a
lock on the disconnect switch and tag the switch
to indicate that maintenance is being performed.
B) Isolate the unit by manually closing the discharge
Stop valve. Allow the unit to equalize to suction
pressure before closing the Suction Bypass. After
the unit has equalized to suction pressure and
suction valve closed, use an acceptable means to
depressurize the unit that complies with all Local,
State and Federal Ordinances.
C) Remove drain plugs from the bottom of compressor housing and the discharge manifold On
units equipped with Suction Oil Injection (SOI)
manually open the SOI solenoid valve below the
compressor. Drain the oil into appropriate containers.

REMOVAL OF COMPRESSOR FROM THE UNIT
After preparing the unit for service, the following steps
should be followed when removing the compressor
from the unit:

Keep compressor alignment shims together and
mark the locations with a permanent marker.
F) On compressors with C-flange the motor/Cflange/compressor assembly must be supported
with a chain fall or other lifting device before the
bolts holding the compressor to the C-flange
adapter can be removed.
G) Install appropriate lifting eye into the threaded
hole on the top of the compressor.
Verify unit is properly secured to avoid compressor
from falling. Re-verify all piping and electrical are
properly disconnected prior to lifting unit.
H) Lift compressor from the base, verify the amount
of room needed for clearance and weight of
the bare compressor when the compressor is
removed from the unit.

Service

INSTALLATION OF THE COMPRESSOR
A) After the work has been completed, reinstall
the compressor on the base or C-flange adapter
(dependent upon compressor model).
B) On the units, replace the shims under the compressor feet. Check for a soft foot. This is accomplished by tightening down three of the hold
down bolts and checking the clearance under the
fourth compressor foot. If there is clearance, add
the appropriate amount of shims. Tighten down
the fourth bolt and loosen either adjacent bolt
and check again for clearance, adding shims accordingly. Align the compressor and motor.
On compressors the discharge elbow should
be tightened on the separator first, before the
compressor manifold flange is tightened. This
should be done to prevent compressor to motor
misalignment.
Replace all electrical, gas and oil connections
removed when servicing the compressor.
LEAK CHECKING UNIT
Note: Unit can be leak checked before evacuation.
CAUTION
Slowly pressurize the unit from the discharge side of the
compressor. Pressurizing the compressor from the suction side may cause rotation of the compressor without
oil supply, which could lead to internal damage.
A) Use a vacuum pump to evacuate the unit.
B) Break the vacuum on the unit using dry nitrogen
and check for leaks. Concentrate on areas where
work was done.
C) If no leaks are found, the unit can be returned to
service.

Service

Top View
Rotor Being Pushed By
Use Of Lever
Direction of rotor movement.
Axial force at coupling
to be 250-300lbs.

Rigidly attach dial indicator.
Position it on the axis of the
compressor.
Force to be determined
by length of level arm.

COMPRESSOR INSPECTION
The Vilter Single Screw Compressor is designed for
long periods of trouble free operation with a minimum of maintenance. However, a yearly inspection
is recommended so any irregular wear is noted and
rectified. At this time, the bearing float is measured
for the main rotor and gate rotors.
The following are the procedures used in measuring
the main rotor and gate rotor bearing float.

Small wooden block or fulcrum.

BEARING CHECK
CAUTION

Side View
Showing gate rotor bearing float
being measured.

Direction of rotor movement.
Axial force at gate rotor to be
250 to 300 lbs.

Wooden block to prevent
damge to gate rotor blade.

When taking the measurements, do not exceed 250
to 300 Lbs. of force at point of contact or damage
may result to the bearings
A) Shut down and de-pressurize the unit.
B) Main rotor bearing float.
1) Remove the coupling guard, then remove
the center member from the coupling.

Force to be determined
Rigidly attach
by length of level arm.
dial indicator.
Use bolt for fulcrum.

2) Attach a dial indicator to the compressor
frame as shown and zero indicator. Place a
lever arm and fulcrum behind the compressor coupling half and push the coupling
towards the motor (note measurement).
TABLE.1 MAXIMUM BEARING FLOAT

Side View
Showing gate rotor bearing float
being measured.

Direction of rotor movement.
Axial force at gate rotor to be
250 to 300 lbs.

Wooden block to prevent
damge to gate rotor blade.

Bearing Float
Maximum Force

MAIN
0.003”
250 to 300
Lbs.

GATE
0.002”
50 to 100
Lbs.

3) Re-Zero indicator, now position the fulcrum
on the motor and use the lever arm to push
the input shaft towards the compressor
(note measurement).
Force to be determined
Rigidly attach
by length of level arm.
dial indicator.
Use bolt for fulcrum.

Service

4) Add both readings, the total indicator movement is the bearing float and this should not
exceed 0.003”.
C) Gate rotor bearing float.
1) Remove the side covers and position a dial
indicator on the gate rotor.
2) Use a lever arm pivoting on a bolt with a small
block of wood against the gate rotor blade to
protect the blade.
3) The maximum amount of bearing float
should not exceed 0.002”.

TABLE 2. GATE ROTOR FLOAT
MODEL
VSM 301 THRU 401
VSM 501 THRU 701
VSS 291 THRU VSS 601
VSS 751 & VSS 901
VSS 1051 THRU VSS 1301
VSS 1551 & VSS 2101

FLOAT
0.045”
0.045”
0.045”
0.055”
0.060”
0.060”

E) NOTE: Readings could be higher than 0.020.
If readings are greater than 0.030 over table
tolerance contact Vilter’s home office.
F) Inspect the main and gate rotors for signs of abnormal wear due to dirt or other contaminants.
G) After the inspection is complete, the covers,
coupling center member and guard can be reinstalled and the unit can then be evacuated and
leak checked before starting.

D) Measure the gate rotor to blade float. Some
movement between blade and support is necessary to prevent damage to the compressor blade,
however at no time should the blade uncover the
support.
1) Position the blade with the gate rotor damper
pin and 90º to the main rotor.
2) Position a dial indicator at the tip of the support. The total movement of the damper pin
in the bushing is the gate rotor float. Refer to
table 0.2 to find the maximum blade to support float (on new compressor parts only).

Service

GATE ROTOR ASSEMBLY CAUTION

Gate rotor removal and assembly is divided into
distinct instructions, instructions for all VSS models
and different instructions for all VSM models. Please
follow the appropriate set of instructions.
For VSM 451 thru 601
compressors, do not
use side rails.

REMOVAL
901A

For VSS 751/901 & VSS 1051 THRU 1301
compressors, use side rails and assemble
to gaterotor stabilizer
as stamped.
901B
901D
901C

Drive End

A) Prepare the compressor for servicing.
NOTE: All parts must be kept with their appropriate side and not mixed when the compressor is reassembled.
B) Remove two upper bolts from the side cover,
and install guide studs in the holes. Remove the
remaining bolts and side cover. There will be
some oil drainage when the cover is removed.
C) Turn the main rotor so a driving edge of any one
of the main rotor grooves is even with the back
of the gate rotor support.
D) Insert the gate rotor stabilizer. The side rails are
not required on VSS 451 thru 601. For the VSS
751 thru 901 and VSS 1051 thru 1301 compressors, use the side rails and assemble to the gate
rotor stabilizer as stamped. For the VSS 1551
thru 3001, use the side rails and assemble to
the gate rotor stabilizer.
The gate rotor stabilizer is designed to hold the
gate rotor support in place and prevent damage
to the gate rotor blade as the thrust bearings and
housing is being removed.

Service

E) Remove the hex head and socket head bolts from
the thrust bearing cover. Insert two of the bolts
into the threaded jacking holes to assist in removing the cover. Retain the shim pack and keep it
with the bearing housing cover.
F) Hold the gate rotor support with a suitable wrench
on the flats provided near the roller bearing housing. Remove the inner retainer bolts and the
retainer. To remove the thrust bearing housing,
install the thrust bearing removal and installation
tool with the smaller puller shoe. Turn the jacking
screw clockwise. The thrust bearings and housing
assembly will be pulled off the shaft and out of the
frame.
G) Remove the bolts on the roller bearing housing.
Thread two bolts into the jack screw holes provided in the housing to assist in removing it.
H) To remove the gate rotor support, carefully move
the support opposite the direction of rotation and
tilt the roller bearing end towards the suction end
of the compressor. The compressor input shaft
may have to be turned to facilitate the removal of
the gate rotor support. On dual gate compressor
units, repeat the procedure for the remaining gate
rotor support assembly.

Service

REMOVAL (ALL VSM 301-701 MODELS)
The removal of the gate rotor assembly for the VSM
301-701 compressors is similar for the VSS 9013001 compressors. The inner races are secured to
the stationary bearing spindle.
A) Prepare the compressor for servicing.
B) Remove the upper bolt from the side cover and
install a guide stud in the hole. Remove the
remaining bolts and side cover. There will be
some oil drainage when the cover is removed.
C) The side cover that contains the suction strainer
should have the suction line properly supported
before the bolts securing the line to the cover
can be removed. After the line is removed, the
cover can be removed per paragraph B.
D) Turn the main rotor so the driving edge of the
groove is between the top of the shelf or slightly
below the back of the gate rotor support. At
this point install the gate rotor stabilizing tool.

Service

E) Remove plug on the thrust bearing housing.
Loosen the socket head cap screw that is located
underneath the plug. This secures the inner races
of the thrust bearings to the spindle.
F) Remove bolts that hold the thrust bearing housing to the compressor. Insert two of the bolts into
the threaded jacking holes to assist in removing
the bearing housing from the compressor. When
the housing is removed, there will be shims between the spindle and thrust bearings. These
control the clearance between the shelf and
gate rotor blades. These must be kept with their
respective parts for that side of the compressor.
G) Remove the bolts from the roller bearing housing.
After the bolts have been removed, the housing
can be removed from the compressor.
H) To remove the gate rotor support, carefully move
the support opposite the direction of rotation
and tilt the roller bearing end towards the suction end of the compressor. The compressor
input shaft may have to be turned to facilitate the
removal of the gate rotor support. On dual gate
versions, repeat the procedure for the remaining
gate rotor support assembly.

Service

INSTALLATION (All VSS Models)
A) Install the gate rotor support by carefully tilting
the roller bearing end of the gate rotor support
towards the suction end of the compressor. The
compressor input shaft may have to be rotated
to facilitate the installation of the gate rotor support.
Install gate rotor stabilizer. The gate rotor stabilizer (901) will hold the gate rotor support
in place as the thrust bearing housing is being
installed. If the gate rotor support is not restricted from moving, the gate rotor blade may
be damaged.
B) Install the roller bearing housing (112) with a
new O-ring (141). Tighten the bolts (152) to the
recommended torque value.
C) When installing the thrust bearing housing
(113), a new O-ring (142) must be used when
the housing is installed. Lubricate the outside of
the housing and bearings with clean compressor
oil to aid in the installation. Due to the fit of the
bearings on the gate rotor shaft, the thrust bearing removal and installation tool with the pusher
shoe must be used. Turn the jacking screw clockwise. This will push the thrust bearings onto the
shaft and push the housing assembly into the
frame. Install the inner retainer (115) and bolts
(151) using Loctite® 242 thread locker. Tighten
the bolts to the recommended torque value.

Service

D) Set the clearance between the gate rotor blade
and the shelf.
1.

Place a piece of 0.003”-0.004” shim stock
between the gate rotor blade and the shelf.

Measure the depth from the top of the compressor case to the top of the thrust bearing
housing. This determines the amount of
shims needed for the correct clearance.

Use factory installed shim pack (106) and
bearing housing cover (116) without the Oring (143). Check the clearance between the
entire gate rotor blade and the shelf, rotate
the gate rotor to find the tightest spot. It
should be between 0.003”-0.004”. Make
adjustments, if necessary. It is preferable to
shim the gate rotor blade looser rather than
tighter against the shelf.

Note: Replacement blades are precisely the same
dimensionally as blades installed originally at factory: Therefore, the same amount of shims will be
required for replacement blades.
E) After clearance has been set install a new O-ring
(143) on bearing housing cover, install cover and
tighten the bolts to the recommended torque
value.
F) Install side cover with a new gasket. Tighten the
bolts to the recommended torque value. The
unit can then be evacuated and leak checked as
outlined in section 0.03.

Service

INSTALLATION (All VSM 301-701 Models)
A) Install the gate rotor support. Carefully tilt the
roller bearing end of the gate rotor support towards the suction end of the compressor. The
compressor input shaft may have to be rotated
to facilitate the installation of the gate rotor
support.
B) Install the roller bearing housing with a new
O-ring. Tighten the bolts to the recommended
torque value.
C) Install the spindle with shims and o-ring, tighten
the bolts to the recommended torque value,
measure the clearance between the shelf and
blade.

Gaterotor for C-flange Models

D) Check the clearance between the entire gate
rotor blade and the shelf, rotate the gate rotor
to find the tightest spot. It should be between
0.003”-0.004”. Make adjustments, if necessary.
It is preferable to shim the gate rotor blade
looser rather than tighter against the shelf.
E) Once the clearance is set remove the spindle.
Install new o-ring, apply Loctite 242 thread
locker to the socket head cap screw clamping
the thrust bearings to the spindle. Torque all
bolts to the recommended torque values.
F) Install side covers with new gaskets. Tighten
bolts to the recommended torque value. The
unit can now be evacuated and leak checked as
outlined in section 0.03.

Service

GATE ROTOR BLADE REMOVAL
A) Remove the gate rotor assembly.
B) Remove the snap ring and washer from the gate
rotor assembly. Lift gate rotor blade assembly off
the gate rotor support.
C) Check damper pin and bushing for excessive wear.
Replace if necessary.

TOP of assembly

Relief area faces TOP of assembly.

Service

GATE ROTOR BLADE INSTALLATION

(with Relief)

A) Install damper pin bushing (120) in gate rotor
blade (111) from the back side of the blade. Be
sure the bushing is fully seated.
B) Place the blade assembly on the gate rotor support. Locating Damper over pin.
C) Install washer (119) and snap ring (130) on gate
rotor assembly. The bevel on the snap ring must
face away from the gate rotor blade. After the
gate rotor blade and support are assembled,
there should be a small amount of rotational
movement between the gate rotor and support.
D) For installation of the gate rotor assembly and
setting of gate rotor clearance, refer to section
INSTALLATION (All VSM 301-701 Models).

GATE ROTOR THRUST BEARING REMOVAL
A) Refer to section INSTALLATION (All VSS Models)
for removal of the gate rotor bearing housings
and gate rotor supports.
B) For removal of thrust bearings on VSM units:
1) Remove bolts (150) from the clamping ring
(114).
2) Remove thrust bearing clamping ring.
3) Remove thrust bearings (126) from housing
(113).
C) For removal of thrust bearings on VSS units:
1) Remove retaining ring from gate rotor support.
2) Remove bearings from support.
3) Remove bearing retainer from inner race.

VSS Models

Service

GATE ROTOR THRUST BEARING INSTALLATION
A) For installation of thrust bearings on VSS units:
1) Install bearings (126) in the housing so the
bearings are face to face.
The larger sides of the inner races are
placed together. A light application of
clean compressor lubricating oil should
be used to ease the installation of the
bearings into the housing.
2) Center the bearing retainer ring on housing, use Loctite® 242-thread locker and
evenly tighten the bolts to the recommended torque value.
3) For installation of the bearing housing and
the setting of the gate rotor blade clearance, refer to section INSTALLATION (All
VSS Models).
B) For installation of thrust bearings on VSM 301701 units:
1) Install retainer in the back of the inner race
of one of the thrust bearings. The back of
the inner race is the narrower of the two
sides.
2) The bearing with the retainer should
be placed in the housing first, retainer
towards the support. Install the second
bearing. The bearings should be positioned face to face. This means that the
larger sides of the inner races are placed
together. A light application of clean compressor lubricating oil should be used to
ease the installation of the bearings into
the gate rotor support.

Inner Retainer

Ball Bearings

Retaining Ring

3) Install the bearing retaining snap ring.
4) For installation of the bearing housing and
the setting of the gate rotor blade clearance, refer to section INSTALLATION (All
VSM Models).

VSM Models

Service

GATE ROTOR ROLLER BEARING REMOVAL
A) Refer to section REMOVAL ( All VSS & VSM) for
removal of the gate rotor bearing housings and
gate rotor supports.
B) Remove the snap ring (131), which retains the
roller bearing in the bearing housing.
C) Remove the roller bearing (125) from the bearing
housing (112).
D) Use a bearing puller to remove the roller bearing
race (125) from the gate rotor support (110).

GATE ROTOR ROLLER BEARING INSTALLATION
A) Match up the part numbers on the inner race to
the part numbers outer race. Press the bearing
race (numbers visible) onto the gate rotor support.
B) Install the outer bearing into the bearing housing
so the numbers match the numbers on the inner
race. Install the snap ring retainer in the housing.
The bevel on the snap ring must face away from
the roller bearing.
C) For installation of the bearing housing, refer to
section INSTALLATION (All VSS & VSM Models).

Service

COMPRESSOR SHAFT SEAL REPLACEMENT

COMPRESSOR SHAFT SEAL REMOVAL
A) Prepare the compressor for servicing as outlined
in section REMOVAL.
B) Remove bolts (281) holding the shaft seal cover
(218). Insert two of the bolts into the threaded
jacking holes to assist in removing the cover.
There will be a small amount of oil drainage as
the cover is removed.
C) Remove the rotating portion of the shaft seal
(219C).
D) Remove oil seal (230) from cover.

Current Shaft Seal and for all Replacements.
(Roll Pin #265 only used on VSS 751 and
larger models.)

E) Remove the stationary portion of the shaft seal
(219B) from the seal cover using a brass drift and
hammer to tap it out from the back side of the
seal cover.

Seal with stationary carbon face (219B)
and rotating mirror face (219C).

Service

Seal Assembly
w/ Stationary Mirror Face

COMPRESSOR SEAL INSTALLATION

NOTE:
When replacing the stationary members of the seal
on the VSS 451 thru VSS 601 the roll pin in the cover
is used only with the seal assembly having a stationary mirror face. If a seal assembly with a stationary
carbon face is installed, the roll pin must be removed.
A) Install new oil seal in cover.
CAUTION
Care must be taken when handling the shaft seal and
mirror face so it is not damaged. Do not touch the
carbon or mirror face as body oil and sweat will cause
the mirror face to corrode.
B) To install the carbon cartridge part of the seal
in the seal cover; clean the seal cover, remove
protective plastic from the carbon cartridge, do
not wipe or touch the carbon face. Lubricate the
sealing O-ring with clean compressor lubricating
oil. If applicable, align the hole on the back of
the carbon cartridge with the dowel pin in the
seal cover. Install cartridge using seal installation
tool or similar (see tool lists).
C) Wipe clean, the compressor input shaft and the
shaft seal cavity in the compressor housing. Apply clean compressor oil to the shaft seal seating
area on input shaft.
D) Lubricate the inside area of the rotating seal with
clean compressor lubricating oil, do not wipe
or touch the face of the rotating portion of the
seal. Align the slot in the rotating seal with the
drive pin on the compressor input shaft. Carefully push the seal on, holding onto the outside
area of the seal until the seal seats against the

Service

shoulder on the input shaft. Make sure the seal
is seated against the shoulder. If the seal is not
fully seated against the shoulder, the shaft seal
carbon will be damaged when the seal cover is
installed.

Maintenance Suggestion:
A spray bottle filled with clean compressor oil
may be used to lubricate the faces of the seals
without touching the seal.

MAIN ROTOR ASSEMBLY
Due to the procedures and tools
involved in the disassembly and
reassembly, the main rotor assembly
must be performed by qualified
individuals. Please consult the factory
if maintenance is required.

E) Install a new O-ring on the seal cover, making
sure the O-ring is placed in the O-ring groove
and not the oil gallery groove. Lubricate both
seal faces with clean compressor lubricating oil.
F) Carefully install the seal cover on the compressor
shaft, evenly tightening the bolts to the recommended torque values.
G) Install the coupling and coupling guard. The unit
can then be evacuated and leak checked.

Service

INSPECTION OF SLIDE VALVE ASSEMBLIES IN
THE COMPRESSOR

Prepare the compressor for servicing.
A) Remove the gate rotor access covers. Using a
mirror and flashlight, visually inspect the slide
valve carriage through the gas bypass opening.
Look for any significant signs of wear on the slide
valve carriage.
B) To check the clearance of the slide valve clamps,
the gate rotor support must be removed. Refer
to removal of the gate rotor support.
C) Using a feeler gauge, inspect the clearance between capacity and volume slide valve clamps
and slide valve carriage through the gas bypass
opening. The clearance should be less than
0.002”.
D) If the slide valves are worn in excess of the tolerances, the factory should be contacted.

REMOVAL SLIDE VALVE CARRIAGE ASSEMBLIES
A) Prepare the compressor for servicing.
B) If only one of the slide valve carriages is removed
only the corresponding gate rotor support
needs to be removed. If both carriages are
removed both gate rotors must be removed.
Remove the gate rotor assemblies.
C) Remove the capacity and volume actuators.
Remove the discharge manifold, capacity and
volume cross shafts and the slide valve racks.

Service

D) Locate and remove the socket head plugs above
the slide valve carriage attachment bolts. Remove the bolts located under the plugs.
E) The slide valve carriage may now be removed.
On newer carriages there is a threaded hole in
the back of the slide valve carriage to aid in its
removal. Use a threaded tip slide hammer to aid
in the removal of the carriage.
Note: Slide Valves may be re-positioned to aid in
removal of assembly.

INSTALLATION OF SLIDE VALVE CARRIAGE ASSEMBLIES
A) Position the slide valves to the center of the carriage. Place the slide valve assembly in the bore of
frame and use the slide hammer to slowly tap the
carriage into position. Re-positioning slide valves
once inside bore may aid installation. Adjust the
carriage so that the 3-holes line up.
B) Install the 3 socket head cap screws with new
Nord-Lock washers beneath the heads, but do
not tighten them.
C) Work a piece of 0.005”shim stock between the
slide valves and the main rotor to help position
the carriage.
D) Tighten, to the correct torque the hold down
bolts to secure the carriage in the frame. The
edges of the slide valves themselves should be
at or slightly below the main rotor bore.
E) Re- Install the capacity and volume slide valve
cross shafts, slide valve racks and discharge
manifold.
F) Re-install the gate rotor assemblies.

Service

COMMAND SHAFT ASSEMBLY REMOVAL
The following steps can be used to remove or install
either the capacity or volume command shaft assemblies.
A) Prepare the compressor for servicing.
B) Follow the appropriate instructions to remove
control actuator.
C) Remove four socket head cap screws (457) and
Nord-Lock washers (477) securing mounting
plate (415) to manifold.
D) The command shaft and mounting plate may
now be removed from the compressor.

457 477

415

B) Install the actuator mounting plate with the four
socket head cap screws and Nord-Lock washers
securing it with proper torque.
C) The unit can now be leak checked.
COMMAND SHAFT BEARING AND O-RING SEAL
REPLACEMENT
A) Remove command shaft assembly.
B) Remove snap ring retainer (451) from command
shaft housing (412). Push the command shaft assembly out of the housing.

COMMAND SHAFT ASSEMBLY INSTALLATION
A) Install the command shaft assembly with a new
o-ring (446) on the manifold. Make sure that the
command shaft tongue is engaged in the cross
shaft slot. Rotate the bearing housing so the
vent holes point down, this will prevent water
and dust from entering the vents.

Service

C) The command shaft bearing (435) is a press
fit on the command shaft (413). Remove the
command shaft bearing with a suitable press.

Ven t ho le.

436
445
Reference “Parts
Section” for current
Housing

D) Remove the O-ring seal (445) from the command shaft housing. The command shaft bushing (433 and 436) might have to be removed to
gain access to o-rings. Replace bushing if the
bore is deeply scored or excessively worn.

DISCHARGE MANIFOLD REMOVAL
A) Remove both control actuators and command
shaft assemblies.
B) On VSS 451-3001 compressors, remove the discharge spool between the manifold and separator.
Remove one bolt from each side of the discharge
manifold and install (2) guide rods approximately
6” long, to support the manifold. Remove the
remaining bolts (note length and location of bolts)
and take off the discharge manifold.
Note: Mainfold has dowel pins to locate it on the
compressor housing. Therefore, remove manifold
straight back approximately 1” as not to break
dowel pins.

COMMAND SHAFT BEARING AND O-RING
SEAL REASSEMBLY
A) Install new O-ring seal in housing and lubricate
the O-ring with clean compressor oil. A vent
hole is provided in the command shaft bearing
housing to allow any refrigerant and oil that may
leak past the O-ring seal to vent to atmosphere
and not into the slide valve motor housing.
Install snap ring retainer and washer on the
command shaft.
B) Remove any burrs from the command shaft to
prevent damage to the O-ring when assembling.
Press the command shaft bearing onto the
command shaft. Insert the command shaft into
the housing applying pressure on outer race of
bearing. Make sure the bearing is fully seated
in the command shaft housing. Install the snap
ring retainer in the command shaft housing.

NOTE:
When removing the discharge manifold on VSM 301-701
compressor the compressor must be properly supported
to keep the compressor from moving when the manifold
is removed.
C) On VSM 301-701 compressors unbolt the discharge flange from the discharge manifold.
D) Remove one bolt from each side of the discharge
manifold and install (2) guide rods approximately
6” long, to support the manifold. Remove the
remaining bolts (note length and location of bolts)
and take off the discharge manifold.

C) Install command shaft assembly.

Service

DISCHARGE MANIFOLD INSTALLATION
A) Install (2) guide rods to position the discharge
manifold. Install a new manifold gasket and
the discharge manifold. Install the dowel pins
and bolts, tighten manifold bolts to the recommended torque value.
B) On VSS 451-3001 compressors install the discharge spool or elbow between the discharge
manifold and oil separator with new gaskets.
When installing the discharge elbow tighten
the bolts to the correct torque on the manifold
flange first before tightening the separator
flange bolts. Install the drain plug in the bottom
of the discharge manifold.
C) On VSM 301-701 compressors install the bolts
in the discharge flange. Install the drain plug in
the bottom of the discharge manifold.
D) Install both command shaft assemblies and
control actuators.

F) Look for any excessive wear on all moving parts
and replace the worn parts.
G) Reassemble the manifold and discharge elbow.
REMOVAL OF CAPACITY OR VOLUME CROSS
SHAFTS
A) Remove the discharge manifold.

SLIDE VALVE GEAR AND RACK INSPECTION
A) Remove the discharge manifold.
B) Check rack to rack clamp and rack clamp spacer
clearance on all four slide valves.
TABLE 4.1
RACK CLEARANCE VALUES
MEASUREMENT
Rack to clamp.
Rack to clamp spacer.

CLEARANCE
0.005 to 0.010”
0.003 to 0.005”

C) Check torque of socket heat cap screws.
D) Check for excessive movement between the
slide valve rack shafts and the rack. The jam nuts
on the end of the slide valve rack shaft should be
tight.
E) Check for loose or broken roll pins in gears.

B) To remove the capacity or volume ratio slide
valve racks, remove the two jam nuts and lock
washers (361) securing the rack (316) to the slide
valve shafts. The racks can now be pulled off the
slide valve shafts. Repeat the procedure for the
remaining pair of slide valve racks.

Service

C) To remove the cross shafts, remove socket head
bolts, clamp and spacers from both sides.
VSS 751-2101 compressors cross shafts.

VSM 301-701 & VSS 2601-3001 compressors
cross shafts
Volume control cross shaft.

INSTALLATION OF CAPACITY OR VOLUME
CROSS SHAFTS
A) To reassemble either set of capacity or volume
ratio slide valve racks, install the cross shaft with
the pinion gear onto the back plate, place the
remaining pinion gear on the shaft and drive in
the roll pins. Install clamps, spacers and bolts
on both sides. Tighten the bolts to the recommended torque values.
B) The slide valve sets must be synchronized on VSS
451-3001 and dual gate VSM 301-701 units. Both
slide valve racks for either the volume ratio or
capacity slide valves must engage the cross shaft
gears at the same time. Push the racks all the way
towards the suction end of the compressor until
they stop. Install washers and jam nuts on the
slide valve shafts. Repeat the procedure for the
remaining set of slide valve racks.

Capacity control cross shaft.

D) Drive the roll pins from pinion gear from one
side. Remove pinion gear. Slide the cross shaft
with the remaining pinion gear or spacers out of
the opposite side. Repeat the procedure for the
remaining cross shaft.

C) Install (2) guide rods to position the discharge
manifold. Install a new manifold gasket and
the discharge manifold. Install the dowel pins
and bolts, tighten manifold bolts to the recommended torque value.

Torque Specifications (ft-lbs)
Type
Bolt

Head
Markings

SAE Grade 2
Coarse (UNC)
SAE Grade 5
Coarse (UNC)
SAE Grade 5
Coarse (UNC)
SAE Grade 8
Coarse (UNF)

Nominal Size Numbers or Inches
#10

1/4

5/16

3/8

7/16

1/2

9/16

5/8

3/4

7/8

155

150*

135

240

387

138

191

338

546

112

115

215

380

614

Socket Head
Cap Screw
(ASTM A574)
Coarse (UNC)
1) Torque values in this table are not to override other specific torque specifications when supplied.
2) When using loctite, torque values in this table are only accurate if bolts are tightened immediately after
loctite is applied.
* The proof strength of Grade 2 bolts is less for sizes 7/8 and above and therefore the torque values are less
than smaller sizes of the same grade.

Torque Specifications for 17-4 Stainless Steel Fasteners (ft-lbs)
Type
Bolt/Nut

Nominal Size Numbers or Inches

Head
Markings
#10

1/4

5/16

3/8

7/16

1/2

9/16

5/8

3/4

Hex & Socket
Head Cap Screws

101

137

245

Nut

NOTE: Continue use of red loctite #271 (VPN 2205E) on currently applied locations. Use blue loctite #243
(VPN 2205F or 2205G) on all remaining locations.

Service

USING A TORQUE WRENCH CORRECTLY

TORQUE WRENCHES
USING A TORQUE WRENCH CORRECTLY INVOLVES FOUR PRIMARY CONCERNS:
A. A smooth even pull to the break point is required. Jerking the wrench can cause the pivot point
to break early leaving the bolt at a torque value lower then required. Not stopping when the
break point is reached results in an over torque condition.
B. When more than one bolt holds two surfaces together there is normally a sequence that
should be used to bring the surfaces together in an even manner. Generally bolting is tightened incrementally in a diametrically staggered pattern. Some maintenance manuals specify
a tightening scheme. If so, the manual scheme shall be followed. Just starting on one side and
tightening in a circle can cause the part to warp, crack, or leak.
C. In some cases threads are required to be lubricated prior to tightening the bolt/nut. Whether
a lubricant is used or not has considerable impact on the amount of torque required to achieve
the proper preload in the bolt/stud. Use a lubricant, if required, or not if so specified.
D. Unlike a ratchet wrench a torque wrench is a calibrated instrument that requires care. Recalibration is required periodically to maintain accuracy. If you need to remove a bolt/nut do not
use the torque wrench. The clockwise/counterclockwise switch is for tightening right hand or
left hand threads not for loosening a fastener. Store the torque wrench in a location where it
will not be bumped around.

Service

A. The Nord-Lock® lock washer sets are used in many
areas in both the VSG & VSSG screw compressors that
require a vibration proof lock washer.
B. The lock washer set is assembled so the course
serrations that resemble ramps are mated together.
C. Once the lock washer set is tightened down, it
takes more force to loosen the bolt that it did to
tighten it. This is caused by the washers riding up
the opposing ramps.

Service

6.00

OIL FILTER ELEMENTS

The following is a description of the oil filter elements
supplied on standard VSS, VSR and VSM single screw
compressor units
6.01

1833C FILTER ELEMENTS

Vilter Part Number

1833C

Usage
Dates

VSS 451 to VSS 1801
All units prior to
3-1-00
18”
6-1/8”

Length
Diameter
A) Characteristics;

1) The outside of the filter element is covered
with a perforated metal surface.
2) At each end of the filter, there is a large thick
elastomeric seal.
3) The housing is a fabricated steel housing
with bolted end cover. The housing can
contain one or two elements.
4) Simplex filter housing is standard with
duplex filter housings with a bypass valve
arrangement is optional, so that the filter
can be changed while unit is in operation.

Service

6.02

KT 721 FILTER ELEMENTS

Vilter Part Number

KT 721

Tank O-Ring
Usage
Dates
Length

2176BU
VSR Compressors
1992 to 8-1-96
8”

A) Characteristics;
1) Pleated type element with a screen covering
the surface of the element.
2) One end of the element is solid while the
other has a pilot hole with a captive “o”-ring.

6.03

KT 722 FILTER ELEMENTS

Vilter Part Number

KT 722

Tank O-Ring
Usage
Dates
Length

2176AJ
VSR Compressors
1996 to 2002
16.8”

A) Characteristics;
1) Pleated type element with a screen covering
the surface of the element.
2) One end of the element is solid while the
other has a pilot hole with a captive “o”-ring.

Service

6.04

KT 773A & B FILTER ELEMENTS

Vilter Part
Number

KT 773A

KT 773B

Tank O-Ring

2176BY

2176BZ

Usage

3109A
3111A
Duplex
Simplex
Housing
Housing
VSM all models 4/1/00 to
present.
VSS 451 to 1301 models with 30”
and smaller oil separators 3/1/00
to present.
16”

Usage 1.
2.
Length

A) Characteristics;
1) Pleated type element with a screen covering the surface of the element.
2) One end of the element is solid while the
other has a pilot hole with a captive “o”ring.
3) On duplex models only the end cap is
removed from the filter bowl

Simplex filter housing.

Duplex filter housing.

B) Usage;
1) Used in simplex and duplex applications.
2) The O-rings for the simplex and duplex
housings are not interchangeable.

Service

6.05

KT 774 FILTER ELEMENTS

Vilter Part
Number
Tank O-Ring
Usage

Length

KT 774
2176BY
3112A
3110A
Simplex
Duplex
Housings
Housings
1. VSS 1501 & 1801 3-1-00 to
present.
2. All other VSS models with
30” and larger oil separators
3/1/00 to present.
39”

C) Characteristics;
1) Pleated type element with a screen
covering the surface of the element.
2) One end of the element is solid while
the other has a pilot hole with a captive
“o”-ring.
3) Only end cap is removed from the filter
bowl.
D) Usage;
1) Used in simplex and duplex applications.

Simplex filter housing.

Maintenance
Refrigeration Maintenance and Inspection Schedule

The following service intervals are based on the usage of Vilter Manufacturing Corporation Premium Grade refrigeration oil in VSS, VSM and VSR Single Screw Compressor units.

5,000

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

Group

SERVICE INTERVAL (HOURS)

R
I

R
S
R
I

S
R
I

R
S
R
I

S
R
I

R
S
R
I

S
R
I

R
S
R
I

S
R
I

R
S
R
I

S
R
I

R
S
R
I

S
R
I

R
S
R
I

200

Inspection
Or
Maintenance
Item

OIL CIRCUIT
Oil Change (1)
Oil Analysis (2)
Oil Filters (3)
Oil Strainer
PACKAGE

CONTROL
CALIBRATION

Coalescing Elements
Suction Screen
Liquid Line Strainers
Coupling Alignment
and Integrity

I
I

R
I
I

I
I

R
I
I

I
I

R
I
I

I
I

R
I
I

Transducers
RTD’s

I
I

COMPRESSOR
Inspect Compressor
Bearings
Key

Notes:

I
R
S

I
I

Inspect.
Replace.
Sample.

(1) The oil should be changed at these intervals, unless oil analysis results exceed the allowable limits.
The frequency of changes will depend on the system cleanliness.
(2) Oil analysis should be done at these intervals as a minimum; the frequency of analysis will depend on
system cleanliness.
(3) The oil filter(s) on a minimum must be changed at these intervals or annually if not run continuously.
However, the oil filter(s) must be changed if the oil filter differential exceeds 12 psi or oil analysis
requires it.

NOTE: See Motor Manual for proper lubrication procedures and service intervals.

VSS Parts Section

Recommended
Spare Parts List
Refer to the Custom Manual
Spare Parts Section for Specific Applications

Please have your Model # and Sales Order # available when ordering.
These are found on the compressor’s Name Plate.

Gate Rotor

125
131
141
130
119

118

111
120
135

110

126

142
143
121 122 123 124

Gate Rotor

MODEL NUMBER

ITEM

102
105
106
110
111
112
113
114
115
116
117
118
119
120A
120B
121
122
123
124
125
126
130
131
135A
135B
141
142
143
150
151
152
153
160

DESCRIPTION
GATE ROTOR BLADE AND BEARING
REPLACEMENT KIT
(111, 118, 120A, 120B, 121, 122, 123, 124,
125, 126, 130, 131, 141, 142, 143)
GATE ROTOR BLADE REPLACEMENT KIT
(111, 118, 120A, 120B, 121, 122, 123, 124,
130, 141, 142, 143)
GATE ROTOR SUPPORT ASSEMBLY
(100, 111, 120B, 119, 130)
GATE ROTOR GASKET SET
(118, 141, 142, 143)
SHIM PACK SET
((2) 121, (2) 122, (1) 123, (1) 124)
SUPPORT
GATE ROTOR
SMALL BEARING HOUSING
LARGE BEARING HOUSING
RETAINER
RETAINER
BALL BEARING COVER
GATE ROTOR COVER
GATE ROTOR COVER GASKET
WASHER
BUSHING, SMALL DOWEL PIN
BUSHING, LARGE DOWEL PIN
SHIM 0.002”
SHIM 0.003”
SHIM 0.005”
SHIM 0.010”
ROLLER BEARING
BALL BEARING
RETAINING RING
RETAINING RING
DOWEL PIN, SM, 0.250” O.D.
DOWEL PIN, LG, 0.4375” O.D.
O-RING ROLLER BEARING HOUSING
O-RING BALL BEARING HOUSING
O-RING BRG HSG COVER
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
SOCKET HEAD CAP SCREW

VSS 451

VSS 601

VSS 751

QTY VPN

QTY

VPN

KT712A

KT712B

KT712C

KT713A

KT713B

KT713C

A25161BB

A25161BA

A25161CB

A25164B

A25164C

2
2
2
2
2
2
2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
2
12
6
40
32
12

A25165B
25606A
25557A
25518A
25517A
25008A
25009A
25258A
25519A
25259A
25007A
25006A
25760A
25010AA
25010AB
25010AC
25010AD
2864B
2865B
2866A
2867A
2868B
25910A
2176M
2176R
2176N
2796AJ
2796B
2796CJ
2796E
2795E

2
2
2
2
2
2
2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
2
12
6
40
32
12

A25165B
25520A
25534A
25518A
25517A
25008A
25009A
25258A
25519A
25259A
25007A
25006A
25760A
25010AA
25010AB
25010AC
25010AD
2864B
2865B
2866A
2867A
2868B
25910A
2176M
2176R
2176N
2796AJ
2796B
2796CJ
2796E
2795E

2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
2
-

A25165C
25612A
25608A
N/A
N/A
N/A
N/A
N/A
N/A
25088A
25086A
25087A
25760B
25089AA
25089AB
25089AC
25089AD
2864C
2865A
2866B
2867E
2868F
25910B
2176N
2176V
2176U
N/A
N/A
N/A
N/A
N/A

Gate Rotor

MODEL NUMBER

ITEM

DESCRIPTION

GATE ROTOR BLADE
AND BEARING
REPLACEMENT KIT
(111, 118, 120A, 120B,
121, 122, 123, 124, 125,
126, 130,131, 141, 142,
143)
GATE ROTOR BLADE
REPLACEMENT KIT
(111, 118, 120A, 120B,
121, 122, 123, 124, 130,
141, 142, 143)
102
GATE ROTOR
SUPPORT ASSEMBLY
(100, 111, 120B, 119,
130)
105
GATE ROTOR
GASKET SET
(118, 141, 142, 143)
110
SUPPORT.
111
GATE ROTOR
118
GATE ROTOR
COVER GASKET
119
WASHER
120A BUSHING, SMALL
DOWEL PIN
120B BUSHING, LARGE
DOWEL PIN
121
SHIM 0.002”
122
SHIM 0.003”
123
SHIM 0.005”
124
SHIM 0.010”
125
ROLLER BEARING
126
BALL BEARING
130
RETAINING RING
131
RETAINING RING
135A DOWEL PIN,
SMALL, 0.3125” O.D.
135B DOWEL PIN,
LARGE, 0.4375” O.D.
141
O-RING ROLLER
BEARING HOUSING
142
O-RING BALL
BEARING HOUSING
143
O-RING BEARING
HOUSING COVER

VSS 901

VSS 1051

VSS 1201

VSS 1301

QTY VPN

QTY

VPN

KT712D

KT712E

KT712F

KT712Y

KT713D

KT713E

KT713F

KT713Y

A25161CA

A25161DB

A25161DA

A25161DH

2
2
2

A25164C
25553A
25554A

2
2
2

A25164D
25614A
25610A

2
2
2

A25164D
25587A
25588A

2
2
2

A25164D
25587A
25588F

2
2

25088A
25086A

2
2

25132A
25086A

2
2

25132A
25086A

2
2

25132A
25086A

25087A

25104A

2
AR
AR
AR
AR
2
4
2
2

25760B
25089AA
25089AB
25089AC
25089AD
2864C
2865A
2866B
2867E

2
AR
AR
AR
AR
2
4
2
2

25760B
25089AA
25089AB
25089AC
25089AD
2864G
2865A
2866B
2867L

2
AR
AR
AR
AR
2
4
2
2

25760B
25089AA
25089AB
25089AC
25089AD
2864G
2865A
2866B
2867L

2
AR
AR
AR
AR
2
4
2
2

25760B
25089AA
25089AB
25089AC
25089AD
2864G
2865A
2866B
2867L

2868F

2868H

25910B

2176N

2176AJ

2176V

2176AM

2176U

Gate Rotor

MODEL NUMBER

ITEM

101
102
105

110
111
112
113
114
115
116
117
118
119
120A
120B
121*
122*
123*
124*
125
126
130
131
135A
135B
141
142
143
150
151
152
153
160

DESCRIPTION
GATE ROTOR BLADE AND BEARING
REPLACEMENT KIT
(111, 118, 120A, 120B, 121, 122, 123, 124,
125, 126, 130, 131, 141, 142 & 143)
GATE ROTOR BLADE REPLACEMENT KIT
(111, 118, 120A, 120B, 121, 122, 123, 124,
130, 141, 142 & 143)
GATE ROTOR ASSEMBLY
(111, 120)
GATE ROTOR SUPPORT ASSEMBLY
(100, 111, 120B, 119, 130)
GATE ROTOR GASKET SET
(118, 141, 142 & 143)
SHIM PACK SET
((2) 121, (2) 122, (1) 123, (1) 124)
SUPPORT
GATE ROTOR
SMALL BEARING HOUSING
LARGE BEARING HOUSING
RETAINER
RETAINER
BALL BEARING COVER
GATE ROTOR COVER
GATE ROTOR COVER GASKET
WASHER
BUSHING, SMALL DOWEL PIN
BUSHING, LARGE DOWEL PIN
SHIM 0.002”
SHIM 0.003”
SHIM 0.005”
SHIM 0.010”
ROLLER BEARING
BALL BEARING
RETAINING RING
RETAINING RING
DOWEL PIN, SM, 0.250” O.D.
DOWEL PIN, LARGE, 0.500” O.D.
O-RING ROLLER BEARING HOUSING
O-RING BALL BEARING HOUSING
O-RING BEARING HOUSING COVER
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
HEX HEAD CAP SCREW
SOCKET HEAD CAP SCREW

VSS 1551

VSS 1851

VSS 2101

QTY VPN

QTY

VPN

KT712L

KT712M

KT712K

KT713G

KT713H

KT713L

A25160EB

A25160EA

A25161EB

A25161EA

A25161EL

A25164E

2
2
2
2
2
2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
12
8
32
44
16

A25165E
25687A
25647A
26507A
26506A
25141A
25789A
25351A
26508A
26509A
25788A
N/A
25760C
25791AA
25791AB
25791AC
25791AD
2864K
2865K
2866G
2867R
N/A
25910C
2176U
2176BD
2176P
2796CJ
2796N
2796CJ
2796R
2795G

2
2
2
2
2
2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
12
8
32
44
16

A25165E
25665A
25645A
26507A
26506A
25141A
25789A
25351A
26508A
26509A
25788A
N/A
25760C
25791AA
25791AB
25791AC
25791AD
2864K
2865K
2866G
2867R
N/A
25910C
2176U
2176BD
2176P
2796CJ
2796N
2796CJ
2796R
2795G

2
2
2
2
2
2
2
2
2
2
2
2
AR
AR
AR
AR
2
4
2
2
2
2
2
2
12
8
32
44
16

A25165E
25495D
25744D
26507A
26506A
25141A
25789A
25351A
26508A
26509A
25788A
N/A
25760C
25791AA
25791AB
25791AC
25791AD
2864K
2865K
2866G
2867R
N/A
25910C
2176U
2176BD
2176P
2796CJ
2796N
2796CJ
2796R
2795G

Shaft Seal
Shaft Seal With Stationary Carbon Face

230

260

219

MODEL NUMBER

ITEM

DESCRIPTION

230
260

SHAFT SEAL AMM KIT
(219, 230, 260)
SHAFT SEAL R22 KIT
(219, 230, 260)
OIL SEAL
O-RING

VSS 291 thru
VSS 601

VSS 751 thru
VSS 1201

VSS 1301

VSS 1551 thru
VSS 2101

QTY VPN

QTY

VPN

KT709A

KT709B

KT709MB

KT709C

1
1
1

KT781A
25040A
2176F

1
1
1

KT781B
25064A
2176AC

1
1
1

KT709MA
2930F
2176AC

1
1
1

KT781C
2930B
2176BH

Main Rotor

201

207

MODEL NUMBER
VSS 451

VSS 601

VSS 751

VSS 901

ITEM

DESCRIPTION

QTY VPN

QTY

VPN

201
207

ROTOR ASSEMBLY
SHIM PACK

1
1

A25226CA
A25177C

A25226BB
A25177B

A25226BA
A25177B

A25226CB
A25177C

MODEL NUMBER
VSS 1051

VSS 1201

VSS 1301

VSS 1551

ITEM

DESCRIPTION

QTY VPN

QTY

VPN

201
207

ROTOR ASSEMBLY
SHIM PACK

1
1

A25226EC
A25177E

A25226DB
A25177D

A25226DA
A25177D

A25752HA
A25177D

MODEL NUMBER
VSS 1851

VSS 2101

ITEM

DESCRIPTION

QTY VPN

201
207

ROTOR ASSEMBLY
SHIM PACK

1
1

A25226ED
A25177E

A25226EE
A25177E

Slide Valve Cross Shafts and End Plate

297

286
222
268
226

269

298

228
VSS 291 THRU VSS 601 ONLY
NO SPACER THIS SIDE OF
SHAFT ASSEMBLY

297

228

226 227
VSS 291 THRU
VSS 601 ONLY

NOTE:
BOTH ACTUATOR SHAFT
ASSEMBLIES ARE IDENTICAL
ON VSS COMPRESSORS.

286

221

269

268

222
298

Slide Valve Cross Shafts and End Plate

MODEL NUMBER
VSS 291 thru
VSS 601

VSS 751
VSS 901

VSS 1051
VSS 1201
VSS 1301

VSS 1551 thru
VSS 2101

ITEM

DESCRIPTION

QTY VPN

QTY

VPN

221
222
226
227
228
267
268
269
270
286

SHAFT
GEAR
RACK CLAMP
RACK CLAMP
SPACER
DOWEL PIN
EXPANSION PIN
EXPANSION PIN
PIPE PLUG
SOCKET HEAD
CAP SCREW
SET SCREW
SET SCREW

2
4
2
2
2
4
4
8

25843A
25027A
25913A
25913B
25847A
N/A
1193D
2981AA
N/A
2795F

2
4
4
4
2
4
4
2
8

25844A
25027A
25913C
N/A
25033C
2868B
1193D
2981AA
2606E
2795F

2
4
4
4
2
4
4
2
8

25845A
25027A
25913C
N/A
25033C
2868B
1193D
2981AA
2606E
2795F

2
4
4
4
2
4
4
2
8

25793A
25027A
25913C
N/A
25033C
2868B
1193D
2981AA
2606A
2795F

2
2

2060J
2060H

2
2

2060J
2060H

2
2

2060J
2060H

2
2

2060J
2060H

297
298

Slide Valve Carriage Assembly
Volume Slide

Capacity Slide

Carriage Assembly

343
345

350
305

304

380
378
347

360

316
323
361
363

300

Slide Valve Carriage Assembly

MODEL NUMBER
VSS 291 thru
VSS 601

VSS 751
VSS 901

VSS 1051
VSS 1201

VSS 1301

ITEM

DESCRIPTION

QTY VPN

QTY

VPN

300
304

CARRIAGE ASSEMBLY
CAPACITY PISTON
(340, 341, 350, 355)
VOLUME PISTON
(340, 342, 350, 355)
GASKET SET
(345)
GASKET SET
(345, 378)
RACK
RACK
SHAFT
PISTON
CAPACITY PISTON
SHAFT
VOLUME PISTON
SHAFT
COVER, ONE PIECE
CAST
GASKET, ONE PIECE
CAST COVER
GASKET, ONE PIECE
CAST COVER
PISTON SLEEVE
PISTON RING SET
EXPANSION PIN
PIPE PLUG
LOCK WASHER
(PAIR)
WASHER
NUT
HEX HEAD CAP
SCREW
HEX HEAD CAP
SCREW
SOCKET HEAD CAP
SCREW
LOCK WASHER
(PAIR)
O-RING
RETAINER RING

A25179B

A25179C

A25179D

A25179DSR

A25183B

A25183C

A25183D

A25183DN

A25184B

A25184C

A25184D

A25184DN

A25200B

N/A

A25200D

2
2
-

N/A
25024A
25023A
N/A
N/A

2
2
2
4

A25200C
25080A
25080B
N/A
25076A

2
2
4

N/A
25080C
25080D
N/A
25138A

2
2
4

N/A
25779B
25080DH
N/A
25138A

N/A

25078A

25078E

25078G

N/A

25078B

25078F

25078H

25399A

25279A

25401A

25900A

25902A

25901A

4
4
6

N/A
N/A
2953AA
1193PP
2606D

2
2
4
4
6

25124A
25079A
2953AB
1193PP
2606D

4
4
6

N/A
N/A
2953AC
1193PP
2606E

4
4
6

N/A
N/A
2953AC
1193PP
2606E

4
4
8

3004C
13265B
2797A

4
4
8

3004C
13265B
2797A

4
4
8

3004C
13265B
2797A

4
4
8

3004C
13265B
2797A

2796B

2796P

N/A

2796BN

N/A

2795N

2795P

N/A
N/A
N/A

6
2
2

3004C
2176Y
2866C

6
-

3004D
N/A
N/A

6
-

3004C
N/A
N/A

305
307A
307B
316
323
325
340
341
342
343
345
346
347
350
355
359
360
361
363
366
367
373
374
378
380

Slide Valve Carriage Assembly

MODEL NUMBER
VSS 1551 thru
VSS 2101
ITEM

DESCRIPTION

QTY VPN

300
304

A25179E

A25183E

A25184E

A25200E

2
2
2
2
4

A25200E
25779A
25780A
25778A
25782A

25784A

25783A

25690A

25384A

4
4
4
6

N/A
25786A
2953AD
1193PP
2606E

4
4
8

3004C
13265B
2797A

2796BL

N/A

2795AG

6
4
4

3004D
2176AG
2755AG

305
307A
307B
316
323
325
340
341
342
343
345
346
347
350
355
359
360
361
363
366
367
373
374
378
380

100

101

Actuator & Command Shaft

400

401

102

446

Actuator & Command Shaft

MODEL NUMBER

ITEM

DESCRIPTION

400

COMMAND SHAFT
ASSEMBLY
SLIDE VALVE
ACTUATOR
O-RING SEAL

401
446

VSS 291 thru
VSS 601

VSS 751
VSS 901

VSS 1051
VSS 1201
VSS 1301

VSS 1551 thru
VSS 2101

QTY VPN

QTY

VPN

A25994B

A25994C

A25994D

A25994E

2
2

25972D
2176X

2
2

25972D
2176X

2
2

25972D
2176X

2
2

25972D
2176X

103

Miscellaneous Frame Components

VSS Screw Compressor
545
545

* 504

513

504

545

514
514

512

506

528
514

536
518

530

536

530
554
536

519

547

536
536

540

536
514
528
545
514

* 504

513
545

104

506

Miscellaneous Frame Components

MODEL NUMBER

ITEM
504A

DESCRIPTION

GASKET & O-RING KIT
FLANGE SET
(513A, 514A, 545A)
504B* FLANGE SET
(513B, 514B, 545B)
504C* FLANGE SET
(513B, 514C, 545C)
506A PLUG SET,
ECONOMIZER
(514C, 528, 545B)
506B PLUG SET,
ECONOMIZER
(514A, 514C, 528,
545C)
512
MANIFOLD GASKET
513A FLANGE
513B FLANGE
514A GASKET
514B GASKET
514C GASKET
518
GASKET, SUCTION
519
GASKET, DISCHARGE
528
ECONOMIZER PLUG
530
O-RING
536
PIPE PLUG 3/4” MPT
540
DOWEL PIN
542
PIPE PLUG 3/4” MPT
545A HEX HEAD CAP
SCREW
545B HEX HEAD CAP
SCREW
545C HEX HEAD CAP
SCREW
547
HEX HEAD CAP
SCREW
554
HEX HEAD CAP
SCREW

VSS 291 thru
VSS 601

VSS 751
VSS 901

VSS 1051
VSS 1201

VSS 1301

QTY VPN

KT710A

KT710B

KT710C

KT710J

A25190A

A25190B

A25190A

A25190B

N/A

A25190B

N/A

A25190D

N/A

A25243BE

A25243CC

A25243DC

A25243DD

1
1
2
1
2
2
1
1
2
2
2
-

N/A
25503A
25058ASW
25058B
11323D
11323E
11323D
25199C
25199B
25397G
2176AB
N/A
2868B
N/A

1
1
2
1
2
1
1
2
2
2
-

N/A
25541A
25058ASW
25058ASW
11323D
N/A
11323S
25199C
25199B
25395A
2176J
N/A
2868B
N/A

1
1
2
1
2
2
1
1
2
2
6
2
-

N/A
25324A
25058B
25058B
11323E
11323E
11323E
25199D
25199C
25391D
2176J
2606A
2868B
N/A

1
1
2
1
2
2
1
1
2
2
6
2
-

N/A
25324A
25058ASW
25058B
11323D
11323E
11323E
25199D
25199C
25391A
2176AB
2606A
2868B
N/A

2796GP

2796C

2796GP

2796C

N/A

2796GP

N/A

2796C

2796GP

2796F

2796U

*Optional

105

Miscellaneous Frame Components

MODEL NUMBER
VSS 1551 thru
VSS 2101
ITEM
504A

DESCRIPTION

GASKET & O-RING KIT
FLANGE SET
(513A, 514A, 545A)
504B* FLANGE SET
(513B, 514B, 545B)
504C* FLANGE SET
(513B, 514C, 545C)
506A PLUG SET,
ECONOMIZER
(514C, 528, 545B)
506B PLUG SET,
ECONOMIZER
(514A, 514C, 528,
545C)
512
MANIFOLD GASKET
513A FLANGE
513B FLANGE
514A GASKET
514B GASKET
514C GASKET
518
GASKET, SUCTION
519
GASKET, DISCHARGE
528
ECON-O-MIZER PLUG
530
O-RING
536
PIPE PLUG 3/4” MPT
540
DOWEL PIN
542
PIPE PLUG 3/4” MPT
545A HEX HEAD CAP
SCREW
545B HEX HEAD CAP
SCREW
545C HEX HEAD CAP
SCREW
547
HEX HEAD CAP
SCREW
554
HEX HEAD CAP
SCREW

*Optional

106

QTY VPN
1

KT710D

A25190C

A25190D

N/A

1
1
1
2
1
2
2
1
1
2
2
3
2
1

A25243ED
25676A
12477C
25058ASW
11323F
11323S
11323G
25199D
25199C
25393A
2176J
2606A
2868K
13163F

11397E

2796GP

11397E

N/A

QTY VPN

107

Replacement Tools

GATE ROTOR
SUPPORT

901

901
BALL BEARING
HOUSING

900

TO REMOVE BEARING
TO INSTALL BEARING

901

FOR VSS 451, VSS 601, DO NOT USE SIDE RAILS.
FOR VSS 751, VSS 901, VSS 1051 AND VSS 1201, ASSEMBLE SIDE RAILS AS STAMPED.
FOR VSS 1551 AND 1801, SIDE RAILS ASSEMBLE ONLY ONE WAY.

108

Replacement Tools

MODEL NUMBER
VSS 291 thru
VSS 601

VSS 751
VSS 901

VSS 1051
VSS 1201
VSS 1301

VSS 1551 thru
VSS 2101

ITEM

DESCRIPTION

QTY VPN

900
901A

GATE ROTOR TOOLS
GATE ROTOR
STABILIZER SET
(901A, 901B, 901C)
GATE ROTOR
STABILIZER SET
(901A, 901B, 901C,
901D)

A25205B

A25205C

A25205E

A25698A

N/A

A25699A

901B

109

110

VSM 301-701 Replacement Parts Section

Recommended
Spare Parts List
Refer to the Custom Manual
Spare Parts Section for Specific Applications

Please have your Model # and Sales Order # available when ordering.
These are found on the compressor’s Name Plate.

111

Gaterotor Assembly

112

Gaterotor Assembly

Part totals indicated are for one gate rotor assembly, machines with two gate rotors will require
double the components listed below.
ITEM

DESCRIPTION

100
101

GATE ROTOR & DAMPER ASSEMBLY

102

GATE ROTOR SUPPORT ASSEMBLY

110
111
114
115
118
119
120
121*
122*
123*
124*
125
126
130
131
132
135
141
143
155
156

100, 101, 119 & 130.
SHIM PACK SET (2) 121, (2) 122,
(1) 123, (1) 124.
SUPPORT.
GATE ROTOR.
SNAP RING.
RETAINER BALL BEARING
GATE ROTOR COVER GASKET.
WASHER WAVE SPRING.
DAMPER.
SHIM 0.002”.
SHIM 0.003”.
SHIM 0.005”.
SHIM 0.010”.
ROLLER BEARING.
BALL BEARING.
RETAINING RING.
RETAINING RING.
RETAINING RING.
DOWEL PIN
O-RING ROLLER BRG HSG.
O-RING BALL BRG SUPPORT.
SHIM
SHIM

SUPPORT ASSEMBLY 110 & 135B.
111,120.

MODEL NUMBER
VSM 301
VSM 361
VSM 401
QTY VPN
QTY VPN
QTY VPN
1
A25222AB 1
A25222AA 1
A25222AC
1

A25160AB 1

A25160AA

A25160AC

A25161AB 1

A25161AA

A25161AC

1
1
1
1
1
1
1
1
AR
AR
AR
AR
1
2
1
1
1
1
1
1
AR
AR

A25165A
25723D
25718B
2867L
25935A
25259B
3203A
25760A
25921AA
25921AB
25921AC
25921AD
2864F
2865L
2866H
2867S
2866J
25910A
2176L
2176F
25977D
25977C

A25165A
25723C
25718C
2867L
25935A
25259B
3203A
25760A
25921AA
25921AB
25921AC
25921AD
2864F
2865L
2866H
2867S
2866J
25910A
2176L
2176F
25977D
25977C

1
1
1
1
1
1
1
1
AR
AR
AR
AR
1
2
1
1
1
1
1
1
AR
AR

1
1
1
1
1
1
1
AR
AR
AR
AR
1
2
1
1
1
1
1
1
AR
AR

A25165A
25723B
25718D
2867L
25935A
25259B
3203A
25760A
25921AA
25921AB
25921AC
25921AD
2864F
2865L
2866H
2867S
2866J
25910A
2176L
2176F
25977D
25977C

AR = As Required

113

Gaterotor Assembly

Part totals indicated are for one gate rotor assembly, dual gate machines will require double the components.
ITEM

DESCRIPTION

100
101

GATE ROTOR & DAMPER ASSEMBLY

102

GATE ROTOR SUPPORT ASSEMBLY

110
111
114
115
118
119
120
121*
122*
123*
124*
125
126
130
131
132
135
141
143
155
156

100, 101, 119 & 130.
SHIM PACK SET (2) 121, (2) 122,
(1) 123, (1) 124.
SUPPORT.
GATE ROTOR.
SNAP RING.
RETAINER BALL BEARING
GATE ROTOR COVER GASKET.
WASHER.
DAMPER.
SHIM 0.002”.
SHIM 0.003”.
SHIM 0.005”.
SHIM 0.010”.
ROLLER BEARING.
BALL BEARING.
RETAINING RING.
RETAINING RING.
RETAINING RING.
DOWEL PIN
O-RING ROLLER BRG HSG.
O-RING BALL BRG SUPPORT.
SHIM
SHIM

SUPPORT ASSEMBLY 110 & 135B.
111,120.

NOTE:

114

*
Not pictured
AR = As Required

MODEL NUMBER
VSM 501
VSM 601
VSM 701
QTY VPN
QTY VPN
QTY VPN
1
A26011BB 1
A26011BA 1
A26011BA
1

A26002BB 1

A26002BA 1

A26002BC

A26003BB 1

A26003BA 1

A26003BC

1
1
1
1
1
1
1
1
AR
AR
AR
AR
1
1
1
1
1
1
1
1
AR
AR

A26035B
26030BB
26032A
2867U
25935B
25259C
25007A
25760A
26027AA
26027AB
26027AC
26027AD
2864B
2865B
2866A
2867A
2866K
25910A
2176M
2176R
25977G
25977H

A26035B
26030BA
26031A
2867U
25935B
25259C
25007A
25760A
26027AA
26027AB
26027AC
26027AD
2864B
2865B
2866A
2867A
2866K
25910A
2176M
2176R
25977G
25977H

A26035B
26030BA
26033A
2867U
25935B
25259C
25007A
25760A
26027AA
26027AB
26027AC
26027AD
2864B
2865B
2866A
2867A
2866K
25910A
2176M
2176R
25977G
25977H

1
1
1
1
1
1
1
1
AR
AR
AR
AR
1
1
1
1
1
1
1
1
AR
AR

Shaft Seal

MODEL NUMBER
ALL VSM 301-401
ALL VSM 501-701
QTY
VPN
QTY
VPN

ITEM

DESCRIPTION

SHAFT SEAL KIT (AMM)
219, 230, & 260.
SHAFT SEAL KIT (HALO)
219, 230, & 260
SHAFT SEAL.
OIL SEAL.
TEFLON SEAL
RETAINER RING
O-RING
O-RING. (205 Only)

*
219
230
244252260
261

NOTE

*
A
-

KT709D

KT709A

1
1
1
1
1
1
1

KT781D
A
2930C
25939A
2928M
2176U
2176AE

1
1
1
1
1
1

KT781A
A
25040A
25939A
2928M
2176F
N/A

Not pictured.
Sold only as kit.
See recommended spare parts lists for complete assembly.

115

Main Rotor, Slide Valve Cross Shafts & End Plate
Models VSM 301-401 Counter Clockwise ONLY

116

Main Rotor, Slide Valve Cross Shafts & End Plate
Models VSM 301-401 Counter Clockwise ONLY

ITEM

DESCRIPTION

201
203

MAIN ROTOR ASSEMBLY.
OIL BAFFLE ASSEMBLY (1)
217, (1) 244, (1) 248, (1) 249, (1) 252.
SHIM ASSORTMENT (2) 240,
(2) 241, (1) 242, (1) 243
END PLATE.
SHAFT.
GEAR.
CLAMP.
SPACER.
SHIM 0.002”
SHIM 0.003”
SHIM 0.005”
SHIM 0.010”
TEFLON RING. (BAFFLE)
CHECK VALVE. (BAFFLE)
CHECK VALVE. (BAFFLE)
RETAINING RING. (BAFFLE)
EXPANSION PIN.
EXPANSION PIN.
PLUG SOLID
HEX HEAD CAP SCREW.
SOCKET HEAD CAP SCREW.
SET SCREW.
SET SCREW.

220
221
222
227
228
240
241
242
243
244
248
249
252
268
269
271**
281
286
297
298

NOTE:

*
**
A

MODEL NUMBER
VSM 301
VSM 361
VSM 401
QTY VPN
QTY VPN
QTY VPN
1
A25226AB 1
A25226AA 1
A25226AC
1

A25942AA 1

A25942AA

1
1
2
4
4
4
A
A
A
A
1
1
1
1
4
4
1
6
8
2
2

A25177A
25719D
25941A
25027A
25913D
25847A
25409AA
25409AB
25409AC
25409AD
25939A
3120A
3120B
2829M
1193D
2981AA
25422A
2796N
2795F
2060J
2060H

1
1
2
4
4
4
A
A
A
A
1
1
1
1
4
4
1
6
8
2
2

Not pictured.
Required at top locate single gaterotor only.
As required.

117

Main Rotor, Slide Valve Cross Shafts & End Plate
Models VSM 501-701 Clockwise ONLY

118

Main Rotor, Slide Valve Cross Shafts & End Plate
Models VSM 501-701 Clockwise ONLY

ITEM

DESCRIPTION

201
203

MAIN ROTOR ASSEMBLY.
OIL BAFFLE ASSEMBLY (1) 217,
(1) 244, (1) 248, (1) 249, (1) 252.
SHIM ASSORTMENT (2) 240,
(2) 241, (1) 242, (1) 243
END PLATE.
SHAFT.
GEAR.
SPACER.
SHIM 0.002”
SHIM 0.003”
SHIM 0.005”
SHIM 0.010”
TEFLON RING. (BAFFLE)
CHECK VALVE. (BAFFLE)
CHECK VALVE. (BAFFLE)
RETAINING RING. (BAFFLE)
WASHER
WASHER
EXPANSION PIN.
EXPANSION PIN.
HEX HEAD CAP SCREW.
SOCKET HEAD CAP SCREW
SET SCREW.
SET SCREW.

220
221
222
228
240
241
242
243
244
248
249
252
255
256
268
269
281
282
297
298

NOTE:

*
A

MODEL NUMBER
VSM 501
VSM 601
VSM 701
QTY VPN
QTY VPN
QTY VPN
1
A26010BB 1
A26010BA 1
A26010BC
1

A26034B

1
1
2
4
4
A
A
A
A
1
1
1
1
2
2
4
4
8
2
2
2

A25177B
26025B
25843A
25027A
25847A
25255AA
25255AB
25255AC
25255AD
25929B
3120A
3120B
2928N
25977E
25977F
1193D
2981AA
2796B
2795D
2060J
2060H

1
1
2
4
4
A
A
A
A
1
1
1
1
2
2
4
4
8
2
2
2

A25177B
26025B
25843A
25027A
25847A
25255AA
25255AB
25255AC
25255AD
25929B
3120A
3120B
2928N
25977E
25977F
1193D
2981AA
2796B
2795D
2060J
2060H

1
1
2
4
4
A
A
A
A
1
1
1
1
2
2
4
4
8
2
2
2

A25177B
26025B
25843A
25027A
25847A
25255AA
25255AB
25255AC
25255AD
25929B
3120A
3120B
2928N
25977E
25977F
1193D
2981AA
2796B
2795D
2060J
2060H

Not pictured.
As required.

119

120

Assembly Includes Carriage and Slides.

Carriage Assembly

Capacity Slide

Volume Ratio
Slide Valve Carriage Assembly

Slide Valve Carriage Assembly

ITEM
300
304
305
316
318
323
325
350
360
361
363
372*

MODEL NUMBER
ALL VSM 301-401
QTY VPN
CARRIAGE ASSEMBLY.
1
A25179A
CAPACITY PISTON 340, 341, 350 & 355. 1
A25183A
VOLUME PISTON 340, 342, 350 & 355. 1
A25184A
CAPACITY RACK.
1
25023D
CAPACITY RACK SHAFT.
1
25772C
VOLUME RATIO RACK.
1
25023C
VOLUME RATIO RACK SHAFT.
1
25772D
PISTON RING SET.
2
2953AE
LOCK WASHER (PAIR).
2
3004C
WASHER.
2
13265B
NUT.
4
2797A
SOCKET HEAD CAP SCREW.
N/A
DESCRIPTION

ALL VSM 501-701
QTY VPN
1
A26012B
1
A25183B
1
A25184B
1
25024A
1
25772A
1
25023A
1
25772B
2
2953AA
2
3004C
2
13265B
4
2797A
1
2795M

Notes:There are two slide valve carriages per compressor. Each one each has its
own Volume Ratio and Capacity slide valves. The above totals are per side of the
compressor, double the quantities if both slide valve carriages are being worked
on.
*.Not Pictured.

121

Actuator & Command Shaft

122

Actuator & Command Shaft

ITEM

DESCRIPTION

400
401
446

COMMAND SHAFT ASSEMBLY
SLIDEVALVE ACUATOR
O-RING SEAL

MODEL NUMBER
VSM 291 thru
VSM 601
QTY VPN

VSS 751 thru
VSS 901
VPN

VSS 1051 thru
VSS 1201
VPN

VSS 1551 thru
VSS 2101
VPN

2
2
2

A25994C
25972D
2176X

A25994D
25972D
2176X

A25994E
25972D
2176X

A25994B
25972D
2176X

123

Miscellaneous Frame Components
Model VSM 301-401

Model VSM 501-701

124

Miscellaneous Frame Components

ITEM

DESCRIPTION

512
514
522
523
528
530
540
542
551
570
571
572
*

MANIFOLD GASKET.
ECON-O-MIZER GASKET.
COUPLING LOCK PLATE
LOCK WASHER
ECON-O-MIZER PLUG.
O-RING
DOWEL PIN
PIPE PLUG
HEX HEAD CAP SCREW
BEARING OIL PLUG
PLUG
SPRING
GASKET / O-RING SET

Notes.

* Not Pictured.

MODEL NUMBER
ALL VSM 301-401 ALL VSM 501 - 701
QTY VPN
QTY VPN
1
25737A
1
26037A
2
11323GG 2
11323D
N/A
1
25004D
N/A
1
3004H
2
25419A
2
25397K
N/A
2
2176BF
2
2868B
2
2868B
3
2606C
10
2606B
N/A
2
2796C
1
25978A
N/A
1
25979A
N/A
1
3148A
N/A
1
KT1075A 1
KT1075B

125

Housing Accessories

Miscellaneous Frame Components

126

Miscellaneous Frame Components

Housing Accessories
ITEM

DESCRIPTION

117
118
129
180
343

GATE ROTOR COVER.
COVER GASKET.
GASKET.
INLET SCREEN.
PISTON COVER. *

MODEL NUMBER
VSM 301 - 701
QTY
VPN
1
25416B
2
25259B
1
11323T
1
25920A
1
25724B

ITEM

DESCRIPTION

MODEL NUMBER
VSM 301 - 401
VSM 501 - 701
QTY VPN
QTY VPN

345
346

O-RING.
O-RING.

4
2

2176BX
2176BG

4
2

2176CA
2176BG

127

Replacement Tools

128

ITEM

DESCRIPTION

901
902

GATEROTOR STABILIZER.
SEAL INSTALLATION TOOL

MODEL NUMBER
ALL VSM 301-401
QTY VPN
1
25742A
1
25455A

ALL VSM 501-701
QTY VPN
1
25742B
1
25455B

Danfoss Liquid Injection Valve Setup

ICM/ICAD Motorized Valve Setup Instructions
The following items need to be setup in order for the valve to operate properly.
1. Press the “Circle” button on the valve. A value of “01” should be shown on the screen.
2. Press the “Circle” button. There should be a value of “1” shown. If not use the up/down
arrows to change it to the correct value. Press the “Circle” button when done.
3. Press the “Up” arrow button. A value of”02” should be shown on the screen.
4. Press the “Circle” button. There should be a value of “1” shown. If not use the up/down
arrow buttons to change it to the correct value. Press the “Circle” button when done.
5. Press the “Up” arrow button. A value of “03” should be shown on the screen.
6. Press the “Circle” button. There should be a value of “2” shown. If not, use the up/down
arrow buttons to change it to the correct value. Press the “Circle” button when done.
7. Press the “Up” arrow button until a value of “04” is shown on the screen.
8. Press the “Circle” button. There should be a value of “50” shown. If not, use the up/down
arrow buttons to change it to the correct value. Press the “Circle” button when done.
9. Press the “Up” arrow button until a value of “07” is shown on the screen.
10. Press the “Circle” button. There should be a value of “1” shown. If not, use the up/down
arrow buttons to change it to the correct value. Press the “Circle” button when done.
11. Press the “Up” arrow button until a value of “10” is shown on the screen.
12. Press the “Circle” button. Press the up/down arrow button to change the value to “11”.
Press the “Circle” button.

129

13. Press the “Up” arrow button until a value of “26” is shown on the screen.
14. Press the “Circle” button. Press the up/down arrow buttons to change the value to the
correct valve that is on the unit. The value number is listed on the valve. The values and
valves are as follows:
0: No valve selected. Alarm A1 will become active.
1: ICM20 with ICAD 600
2: ICM25 with ICAD 600
3: ICM32 with ICAD 600
4: ICM40 with ICAD 900
5: ICM50 with ICAD 900
6: ICM65 with ICAD 900
15. Press the “Circle” button.
The valve is now ready to be used.

Note:
Refer to the appropriate controller manual for control setup.

130

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Contents

Page
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Wiring the ICAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
ICAD Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
ICAD Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Troubleshooting
The Manual Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Service parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Common questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

DKRCI.EI.HT0.A1.22 / 520H1639

¢ Danfoss (USCO / MKS), 11- 2006

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Care should be taken to protect the ICM function module while it is removed from the
valve body.
3. Weld the valve body in line making sure the arrow on the valve body is pointing in
the direction of flow.
4. Remove all debris from the valve body before re-installing the bonnet.
5. Install the bonnet/function module into the valve body.
a. For ICM 20, make sure that the removable orifice seat is installed in the valve body
with the small O-ring between the orifice seat and body. Make sure the bonnet gasket
is installed and in good condition.
b. For ICM 25 through ICM 65, check that the two O-rings on the bonnet and gasket
located between the bonnet and valve body are installed and in good condition. A
light coating of refrigerant oil on the bonnet O-rings will facilitate installation of the
bonnet.
6. Install the four bolts and torque to the following specifications:
Valve body

ft lbs

ICM 20

ICM 25

ICM 32

ICM 40

ICM 50

100

ICM 65

110

7. Install the ICAD motor actuator on the ICM valve:
a. The ICM valve must not be in its fully opened position while the ICAD motor is
calibrated with the valve at a later step. Therefore, if the opening degree of the ICM
valve was changed from the factory setting, it should be set to an opening degree
between 0% and 75% using the manual magnet tool. To easily ensure correct
positioning, turn the manual tool counter-clockwise until it is clear that it cannot be
turned further.
b. Make sure that the ICM adapter/valve stem and inner ICAD motor magnets are
completely dry and free from any debris.
c. For applications below freezing, the ICM adapter O-ring (position 2c in the diagram
on page 3) must be removed, and Molycote G 4500 grease (supplied with ICAD
motor) needs to be applied in the O-ring groove on the adapter and on the O-ring
before it is re-installed on the ICM adapter. The Molycote grease ensures a good seal
between the ICAD motor and the ICM adapter to prevent moisture from entering the
ICAD magnets.
d. Place the ICAD motor on the valve stem.
e. Push the ICAD motor completely down to the identification ring on the valve stem
and use a 2.5 mm hex key to tighten the set screws evenly so the ICAD motor is
centered on the ICM adapter (torque: 3 Nm/ 2.5 lb-ft).

DKRCI.EI.HT0.A1.22 / 520H1639

¢ Danfoss (USCO / MKS), 11- 2006

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Wiring the ICAD

Note: The ICAD is powered by a 24 Volt DC power source.
There are two cables pre-mounted and connected to the ICAD motor actuator. Never try to
open the ICAD motor because the special moisture seal will be damaged.
The power cable consists of 3 wires:
• Green: (–) common (ground)
• Brown: (+) positive from 24VDC power source
• White: (+) positive from UPS/battery backup (optional)
The control cable consists of 7 wires:
• Yellow: (–) common (ground)
(+) positive 4-20mA or 0-20mA input to control ICAD motor
• Gray:
(+) positive 4-20mA or 0-20mA output from ICAD for valve
• Blue:
position feedback
• Pink:
(+) positive 2-10V or 0-10V input to control ICAD motor. Also used as a
digital input with the yellow wire for on/off solenoid valve operation.
• White: common alarm (digital NPN transistor output when combined with
yellow wire)
• Brown: indicates ICM is fully open (digital NPN transistor output when combined
with yellow wire)
• Green: indicates ICM is fully closed (digital NPN transistor output when combined
with yellow wire)

Electrical Data
Supply voltage is galvanically isolated from input and output wires.
Supply voltage
24 V d.c., +10% / -15%
Load ICAD 600: 1.2 A
ICAD 900: 2.0 A
Fail safe supply
Min. 19 V d.c.
Load ICAD 600: 1.2 A
ICAD 900: 2.0 A
Anolog input - Current or Voltage
Current
0/4 - 20 mA
Load: 200 Ω
Voltage
0/2 - 10 V d.c.
Load: 10 kΩ
Analog output
0/4 - 20 mA
Load: ≤ 250 Ω
Digital input - Digital ON/OFF input by means of voltfree contact (Signal/Telecom relays with
gold-plated contacts recommended) – Voltage input used
ON: contact impedance < 50 Ω)
OFF: contact impedance > 100 kΩ
Digital output - 3 pcs. NPN transistor output
External supply: 5 - 24 V d.c. (same supply as for ICAD can be used, but please note that the
galvanically isolated system will then be spoiled).
Output load:
50 Ω
Load:
Max. 50 mA

¢ Danfoss (USCO / MKS), 11 - 2006

DKRCI.EI.HT0.A1.22 / 520H1639

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Programming the ICAD

When the ICAD motor is first powered, the ICAD display will flash an A1 alarm. This means
that the ICM valve size that is being used with the ICAD motor needs to be selected in
parameter ¡26. Parameter ¡26 is password protected and will not appear in the parameter list
until the user enters the password in parameter ¡10. The password is “11,” and will allow the
user to access parameter ¡26 where the appropriate valve size is selected. When the ICM
valve size is selected, the ICAD will calibrate itself to the ICM valve and will then be ready for
control by a 4-20mA signal. For most applications, this is the only programming that will
need to be done if the ICAD is going to be controlled by a 4-20mA input.

ICAD Parameters
Description
ICM OD (Opening
Degree)

Display
name

Min.

Max.

Factory
setting

Unit

Comments

100

ICM valve Opening Degree is displayed during normal operation.
Running display value (see ¡01, ¡05).

Main Switch

¡01

Internal main switch
1: Normal operation
2: Manual operation. Valve Opening Degree will be flashing. With the down arrow
and the up arrow push buttons the OD can be entered manually.

Mode

¡02

Operation mode
1: Modulating – ICM positioning according to Analog Input (see ¡03)
2: ON/OFF - operating the ICM valve like an ON/OFF solenoid valve controlled via
Digital Input. See also ¡09.

Type of Analog Input signal from external controller
1: 0 - 20 mA
2: 4 - 20 mA
3: 0 - 10 V
4: 2 - 10 V

Analog Input signal

¡03

Speed at ON/OFF and
Modulating Mode

¡04

100

Speed can be decreased. Max. speed is 100 %
Not active when ¡01 = 2
If ¡02 = 2 the display will indicate speed in display. Low, Med and High also
means ON/OFF operation.
If ¡04 < = 33,
Low is displayed
33 < If ¡04 < = 66, Med is displayed
If ¡04 > = 67
High is displayed

Automatic calibration

¡05

Not active before ¡26 has been operated.
Always auto reset to 0.
CA” will flash in the display during calibration, if Enter push button has been
activated for two seconds.

Analog Output signal

¡06

Type of A0 signal for ICM valve position
0: No signal
1: 0 - 20 mA
2: 4 - 20 mA

Define condition at power cut when fail safe is installed.
1: Close valve
2: Open valve
3: Maintain valve position
4: Go to OD given by ¡12

Fail safe

¡07

Digital Input function

¡09

Password

¡10

199

Enter number to access password protected parameters: ¡26
Password = 11

Old Alarms

¡11

A99

Old alarms will be listed with the latest shown first. Alarm list can be reset by
means of activating down arrow and up arrow at the same time for 2 seconds.

OD at powercut

¡12

100

Only active if ¡07 = 4
If fail safe supply is connected and powercut occurs ICM will go to entered OD.

ICM configuration

¢ Danfoss (USCO / MKS), 11 - 2006

¡26

DKRCI.EI.HT0.A1.22 / 520H1639

Define function when DI is ON (short circuited DI terminals) when ¡02 = 2
1: Open ICM valve (DI = OFF = > Close ICM valve)
2: Close ICM valve (DI = OFF = > Open ICM valve)

NB: Password protected. Password = 11
At first start up A1 will flash in display. Enter valve type
0: No valve selected. Alarm A1 will become active.
1: ICM20 with ICAD 600
2: ICM25 with ICAD 600
3: ICM32 with ICAD 600
4: ICM40 with ICAD 900
5: ICM50 with ICAD 900
6: ICM65 with ICAD 900

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Troubleshooting

The manual tool should always be ordered with any ICM/ICAD assembly. This tool gives the
user the ability to remove the ICAD actuator and manually rotate the valve in the open or
close direction depending on need and application. When using the manual tool, a clockwise rotation will open the valve and a counter-clockwise rotation will close the valve.

The Manual Tool

NOTE:
It is very important to remember that when rotating the valve manually you are changing
the position from that in the actuator’s memory. If power is removed from the actuator prior
to using the manual tool, no problem will occur because, once the ICAD is powered up again,
it will automatically recalibrate to the fully closed position before returning to the position in
memory to which the control signal last set the valve. This recalibration will not occur if
power is not removed from the ICAD prior to using the manual tool, and erroneous operation
will likely occur. Always remove power before using the manual tool, and restore power
afterward to ensure recalibration and trouble-free operation.
Service Parameters

The user will be able to troubleshoot and determine many of the conditions and set points
within the ICAD by accessing the Service Menu. A list of those service parameters follows
below:
Service Menu
Description

Display
Min.
name

Max. Unit Comments

OD %

¡50

100

AI [mA]

¡51

ICM valve Opening Degree
Analog Input signal

AI [V]

¡52

Analog Input signal

AO [mA]

¡53

¡54

Digital Input signal

Analog Output signal

DO Close

¡55

Digital Output Closed status. ON when OD < 3 %

DO Open

¡56

Digital Output Open status. ON when OD > 97 %

DO Alarm

¡57

Digital Output alarm status. ON when an alarm is detected

MAS mP SW
ver.

¡58

100

Software version for MASTER Microprocessor

SLA mP SW ver.

¡59

100

Software version for SLAVE Microprocessor

It is also possible to restore the original factory settings to the ICAD by the following
procedure:
To restore factory settings:
1. Remove the power supply.
2. Activate down arrow and up arrow push buttons at the same time.
3. While holding the up and down arrow reconnect the power supply.
4. Release down arrow and up arrow push buttons.
5. When the display on ICAD is alternating between showing: CA and A1 the factory
resetting is complete.

DKRCI.EI.HT0.A1.22 / 520H1639

¢ Danfoss (USCO / MKS), 11- 2006

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Alarms

There are a number of alarms which are excellent indicators of improper installation or
set-up:
Description

Troubleshooting Tips

ICM
Comments
alarm text

No valve type selected

At start-up A1 and CA will be displayed

Controller fault

Internal fault inside electronics

Input error

Not applicable if ¡01 = 2 or ¡02 = 2
When ¡03 = 1 and AI > 22 mA
When ¡03 = 2 and AI > 22 mA or AI < 2 mA
When ¡03 = 3 and AI >12 V
When ¡03 = 4 and AI >12 V or AI < 1 V

Low voltage of fail safe supply

If 5 V d.c. < Fail safe supply
< 18 V d.c.

Check Supply to ICAD

If supply voltage < 18 V d.c.

Problem

Possible cause and solution

The valve is not working and an A1 is
flashing in the display.

The ICM valve size was not selected in
parameter ¡26. See the programming
section on page 9.

The valve does not appear to be opening
or closing properly

1. The ICAD was not mounted properly
on the valve stem. Solution: Check to
make sure that the ICAD was mounted
evenly on the ICM valve
2. The ICAD is not receiving a proper
input signal. Solution: Use the service
parameters (¡51 for a mA input or ¡52
for a voltage input) to check the input
signal that the ICAD is receiving.

The valve position feedback signal is not
working when using customer supplied
controller/PLC

1. A power supply was installed in the
4-20mA/0-20mA feedback loop.
The ICAD motor actuator supplies
the power for the 4-20mA/0-20mA
feedback loop. Solution: Remove any
power source that may be supplied to
the feedback loop.
2. Wiring problem. Solution: Check the
service parameter ¡53 to see what the
ICAD is outputting. If this does not
reveal anything, check the current
output (yellow and blue wires in ICAD
control cable) with an ammeter.
3. The feedback output signal was turned
off in parameter ¡06. Solution: Check
to make sure the setting in parameter
¡06 is correct.

For all other problems, contact Danfoss.

¢ Danfoss (USCO / MKS), 11 - 2006

DKRCI.EI.HT0.A1.22 / 520H1639

ICM/ICAD Motorized Valve

Installation, Programming, and Troubleshooting

Common Questions

What happens in the event of a power failure?
The ICAD will remain in the position it is in when power is lost. There are two ways to
address this condition:
• Add a UPS (Uninterruptible Power Supply) to the power wiring. This is easily
accomplished with the green and white wires in the power cable. A UPS is
available from Danfoss. The UPS can provide service for up to 9 ICAD 600’s or up
to 6 ICAD 900’s.
Note: The UPS is not a continuous power supply. It is used to change the valve
position (usually to close the valve) in the event of a power failure. Therefore, the
system is not to be run in the UPS mode.
• Add a solenoid valve in front of the ICM. This is a very simple solution provided
that there is no issue associated with the additional pressure drop through the
solenoid valve.
How much power do I need to supply to the ICAD?
The total power required depends on both the ICAD size and the number of ICAD’s powered
by the DC power supply. The power for each ICAD is:
• For the ICAD 600 (used on ICM 20, 25, and 32), the power requirement is
approximately 30 W
• For the ICAD 900 (used on ICM 40, 50, and 65), the power requirement is
approximately 50 W
How can I monitor the valve position remotely?
The control wiring provides for a 4 to 20 mA or 0 to 20 mA signal output (blue and yellow
wires). This signal can be sent to:
• A remote display
• A PLC or PC
• Another ICAD motor to give the same opening position

Danfoss · Refrigeration & Air-Conditioning Division · 7941 Corporate Drive · Baltimore, MD 21236
Ph 410-931-8250 · Fax 410-931-8256 · E-mail: baltimore@danfoss.com · Internet: www.danfoss.com/North_America

DKRCI.EI.HT0.A1.22 / 520H1639

¢ Danfoss (USCO / MKS), 11- 2006

Appendix A: Pre Start Up for Remote Oil Coolers

143

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.6
Linearized                      : Yes
Create Date                     : 2012:10:01 15:25:05Z
Modify Date                     : 2013:06:10 08:23:20-05:00
Has XFA                         : No
XMP Toolkit                     : Adobe XMP Core 5.2-c001 63.139439, 2010/09/27-13:37:26
Format                          : application/pdf
Creator                         : 
Title                           : 35391S - Rev 08b - Booklet.indb
Creator Tool                    : Adobe InDesign CS5.5 (7.5.3)
Metadata Date                   : 2013:06:10 08:23:20-05:00
Producer                        : GPL Ghostscript 8.15
Document ID                     : uuid:f034732e-15f1-42eb-8954-7e0eff7fb4ac
Instance ID                     : uuid:a393bf8c-aae7-4dc2-a916-fad77c99fbb9
Page Layout                     : SinglePage
Page Count                      : 145

EXIF Metadata provided by EXIF.tools

Emerson Vsm Users Manual 35391S Rev 08b Booklet.indb

Emerson Air Compressor 450XL 35391S_Rev_08b

0020ab6d-0f13-4264-953b-fba9d83b13ec Emerson Air Compressor VSR User Guide |

Navigation menu

Versions of this User Manual:

Views

Navigation