Greenheck Fan Make Up Air Unit 470658 Msx Users Manual

470658 MSX to the manual 607ed3d4-d8c5-4d8f-a190-90d48b12459f

2015-02-09

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Part #470658
MSX
Make-Up Air Unit

Installation, Operation and Maintenance Manual
Please read and save these instructions. Read carefully before attempting to assemble, install, operate or maintain the
product described. Protect yourself and others by observing all safety information. Failure to comply with instructions
could result in personal injury and/or property damage! Retain instructions for future reference.

2. The rotation of the wheel is critical. It must be free
to rotate without striking or rubbing any stationary
objects.
3. Motor must be securely and adequately grounded.
4. Do not spin fan wheel faster than maximum
cataloged fan rpm. Adjustments to fan speed
significantly effects motor load. If the fan RPM is
changed, the motor current should be checked to
make sure it is not exceeding the motor nameplate
amps.
5. Do not allow the power cable to kink or come in
contact with oil, grease, hot surfaces, or chemicals.
Replace cord immediately if damaged.
6. Verify that the power source is compatible with the
equipment.
7. Never open blower access doors while the fan is
running.

General Safety Information
Only qualified personnel should install this unit.
Personnel should have a clear understanding of these
instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock, possible injury due to coming in contact with
moving parts, as well as other potential hazards.
Other considerations may be required if high winds
or seismic activity are present. If more information
is needed, contact a licensed professional engineer
before moving forward.
1. Follow all local electrical and safety codes, as well
as the National Electrical Code (NEC), the National
Fire Protection Agency (NFPA), where applicable.
Follow the Canadian Electric Code (CEC) in
Canada.
DANGER

IMPORTANT
All factory provided lifting lugs must be used when
lifting any unit. Failure to comply with this safety
precaution could result in property damage, serious
injury or death.

WARNING
Disconnect all electrical power to the fan and secure
to the “OFF” position prior to inspection or servicing.
Failure to comply with this safety precaution could
result in serious injury or death.

WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage,
injury or death. Read the installation, operating
and maintenance instructions thoroughly before
installing or servicing this equipment.

Always disconnect power before working on or
near a unit. Lock and tag the disconnect switch or
breaker to prevent accidental power up.
CAUTION
When servicing the unit, motor may be hot enough
to cause pain or injury. Allow motor to cool before
servicing.

Model MSX Make-Up Air

Receiving
Upon receiving the product check to make sure all
items are accounted for by referencing the bill of
lading to ensure all items were received. Inspect
each crate for shipping damage before accepting
delivery. Notify the carrier if any damage is noticed.
The carrier will make notification on the delivery
receipt acknowledging any damage to the product.
All damage should be noted on all the copies of the
bill of lading which is countersigned by the delivering
carrier. A Carrier Inspection Report should be filled
out by the carrier upon arrival and reported to the
Traffic Department. If damaged upon arrival, file claim
with carrier. Any physical damage to the unit after
acceptance is not the responsibility of Greenheck Fan
Corporation.

Unpacking
Verify that all required parts and the correct quantity
of each item have been received. If any items are
missing, report shortages to your local representative
to arrange for obtaining missing parts. Sometimes it
is not possible that all items for the unit be shipped
together due to availability of transportation and truck
space. Confirmation of shipment(s) must be limited to
only items on the bill of lading.

Handling
Units are to be rigged and moved by the lifting
brackets provided or by the skid when a forklift is
used. Location of brackets varies by model and size.
Handle in such a manner as to keep from scratching
or chipping the coating. Damaged finish may reduce
ability of unit to resist corrosion.

Storage
Units are protected against damage during shipment.
If the unit cannot be installed and operated
immediately, precautions need to be taken to prevent
deterioration of the unit during storage. The user
assumes responsibility of the unit and accessories
while in storage. The manufacturer will not be
responsible for damage during storage. These
suggestions are provided solely as a convenience to
the user.

INDOOR — The ideal environment for the storage of

units and accessories is indoors, above grade, in a
low humidity atmosphere which is sealed to prevent
the entry of blowing dust, rain, or snow. Temperatures
should be evenly maintained between 30°F (-1°C) and
110F (43°C) (wide temperature swings may cause
condensation and “sweating” of metal parts). All
accessories must be stored indoors in a clean, dry
atmosphere.
Remove any accumulations of dirt, water, ice, or snow
and wipe dry before moving to indoor storage. To
avoid “sweating” of metal parts allow cold parts to
reach room temperature. To dry parts and packages
use a portable electric heater to get rid of any
moisture build up. Leave coverings loose to permit air
circulation and to allow for periodic inspection.
2

Model MSX Make-Up Air

The unit should be stored at least 3½ in. (89 mm) off
the floor on wooden blocks covered with moisture
proof paper or polyethylene sheathing. Aisles between
parts and along all walls should be provided to permit
air circulation and space for inspection.

OUTDOOR — Units designed for outdoor applications

may be stored outdoors, if absolutely necessary.
Roads or aisles for portable cranes and hauling
equipment are needed.
The fan should be placed on a level surface to prevent
water from leaking into the unit. The unit should be
elevated on an adequate number of wooden blocks so
that it is above water and snow levels and has enough
blocking to prevent it from settling into soft ground.
Locate parts far enough apart to permit air circulation,
sunlight, and space for periodic inspection. To
minimize water accumulation, place all unit parts on
blocking supports so that rain water will run off.
Do not cover parts with plastic film or tarps as these
cause condensation of moisture from the air passing
through heating and cooling cycles.

Inspection and Maintenance during Storage
While in storage, inspect fans once per month. Keep a
record of inspection and maintenance performed.
If moisture or dirt accumulations are found on parts,
the source should be located and eliminated. At each
inspection, rotate the fan wheel by hand ten to fifteen
revolutions to distribute lubricant on motor. Every
three months, the fan motor should be energized. If
paint deterioration begins, consideration should be
given to touch-up or repainting. Fans with special
coatings may require special techniques for touch-up
or repair.
Machined parts coated with rust preventive should
be restored to good condition promptly if signs of
rust occur. Immediately remove the original rust
preventive coating with petroleum solvent and clean
with lint-free cloths. Polish any remaining rust from
surface with crocus cloth or fine emery paper and oil.
Do not destroy the continuity of the surfaces. Wipe
thoroughly clean with Tectyl® 506 (Ashland Inc.) or
the equivalent. For hard to reach internal surfaces or
for occasional use, consider using Tectyl® 511M Rust
Preventive or WD-40® or the equivalent.

REMOVING FROM STORAGE — As units are removed
from storage to be installed in their final location,
they should be protected and maintained in a similar
fashion, until the equipment goes into operation.
Prior to installing the unit and system components,
inspect the unit assembly to make sure it is in working
order.
1. Check all fasteners, set screws on the fan,
wheel, bearings, drive, motor base, and
accessories for tightness.
2. Rotate the fan wheel(s) by hand and assure no
parts are rubbing.

Table of Contents

Installation of Indoor Unit

Installation

Clearance to Combustibles/Service Clearances. . 3
Indoor Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unit Arrangement DB / HZ / UB. . . . . . . . . . . . . . . 4
Roof Mounted Unit — Arrangement DBC. . . . . 5-6
Optional Evaporative Cooling Module. . . . . . . . . . 7
Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Optional Electrical Heater. . . . . . . . . . . . . . . . . . . . 9
Optional Evaporative Cooling Piping. . . . . . . 10-11
Optional Water Wizard™ . . . . . . . . . . . . . . . . . . . 12
Optional Direct Expansion (DX) Coil Piping. . 13-14
Optional Chilled Water Coil Piping. . . . . . . . . . . . 14
Optional Building Pressure Control. . . . . . . . . . . 15

Start-Up

Blower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-17
Optional Electric Heater. . . . . . . . . . . . . . . . . . . . 18
Optional Evaporative Cooling Recirculating. . . . 19
Optional Water Wizard™ . . . . . . . . . . . . . . . . 20-21

Operation

Optional VAV Units . . . . . . . . . . . . . . . . . . . . . . . .
Optional Recirculating Units. . . . . . . . . . . . . . . . .
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Water Wizard™ . . . . . . . . . . . . . . . . . . .

Troubleshooting

Blower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor Overamps. . . . . . . . . . . . . . . . . . . . . . . . . .
Insufficient / Too Much Airflow. . . . . . . . . . . . . . .
Excessive Noise or Vibration. . . . . . . . . . . . . . . .
Optional Electric Heater. . . . . . . . . . . . . . . . . . . .
Optional Evaporative Cooling. . . . . . . . . . . . . . . .
Optional Water Wizard™ . . . . . . . . . . . . . . . . . . .

22
23
24
25
26
27
28
29
30
31
32

Maintenance

Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33-35
Fall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Reference

Control Center Layout / Dirty Filter Switch. . . . . 37
Start-Up Check List . . . . . . . . . . . . . . . . . . . . . . . 38
Maintenance Log . . . . . . . . . . . . . . . . . . . . . . . . . 39
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . Backcover

Clearance to Combustibles /
Service Clearances
Insulated/
Units
Non Insulated
Units

Install threaded hangers from ceiling supports. When
locating hangers, allow enough room to open access
panel(s). Two nuts must be used on the end of each
threaded hanger. Ceiling supports are supplied by
others.

2. Install Unit

Using sheet metal screws, attach the weatherhood/
thru-wall/filter section to the blower/burner section.
The flange on the weatherhood/thru-wall/filter section
should overlap the flange on the blower/burner section.
Raise the assembled unit into place.
Using two nuts per hanger, fasten the unit supports to
the hangers under the unit. Appropriate unit supports,
such as the optional Greenheck hanging bracket kit or
c-channel and angle iron (supplied by others) should be
used.
Using self
tapping
screws,
attach
ductwork to
unit.

Ceiling Supports

Ductwork

In order to
prevent the
unit from
Hangers
Unit Supports
swinging
and to
provide
Indoor Mounting
a safe
environment for service and maintenance, additional
measures must be taken to secure the unit in all
directions.
NOTE
Two nuts must be used on each end of each
threaded hanging rod for proper support.
NOTE

Floor
0 inches

Top
0 inches

Sides
0 inches

Ends
0 inches

(0 mm)

0 inches

6 inches

(0 mm)

(152.4 mm)

Clearance to combustibles is defined as the minimum distance
required between the heater and adjacent combustible surfaces to
ensure the adjacent surface’s temperature does not exceed 90 degrees
above the ambient temperature.

Recommended Minimum Service Clearances
42 inches (1066.8 mm)
Housing 32 and less
on the controls side of the unit
48 inches (1219.2 mm)
Housing 35 and higher
on the controls side of the unit
Clearances for component removal (such as evaporative cooler media)
may be greater than the service clearances listed.

1. Install Hangers

Good duct practices should be followed for
all ductwork. Ductwork should be installed in
accordance with SMACNA and AMCA guidelines,
NFPA 96 and any local codes. Reference the CAPS
submittal for duct sizes.

3. Seal Wall Opening
Apply sealant around
the perimeter of the
weatherhood to prevent
water penetration and
drafts into the building.

Sealant

Seal Wall Opening
Model MSX Make-Up Air

Installation of
Arrangement DB / HZ / UB
1. Install Curb and/or Equipment
Support(s)

Position curb/equipment support(s) on the roof
(reference the CAPS submittal for placement of curb/
equipment support(s) in relation to the unit). Verify
that unit supports are level, shim if necessary. Attach
curb to roof and flash into place. Attach the equipment
support(s) to the roof, remove metal cover, flash to
wooden nailer and reinstall cover.
Roof Curb
Metal Cover

NOTE
The use of all lifting lugs and a set of spreader bars
is mandatory when lifting the unit.
NOTE
Some units come with the weatherhood attached
and Step 5 may not apply.

5. Assemble and Attach Weatherhood

The weatherhood can now be assembled and
attached to the unit. Detailed assembly instructions
can be found with the weatherhood. If the optional
evaporative cooling module was selected, this step
does not apply, refer to the Installation of the Optional
Evaporative Cooling Module section, page 7.

6. Seal Weatherhood Seam

Using an appropriate sealant, seal the seam between
the weatherhood and the unit.

Equipment
Support

Roof Curb and Equipment Support

2. Install Ductwork

Good duct practices should be followed for all ductwork.
All ductwork should be installed in accordance with
SMACNA and AMCA guidelines, NFPA 96 and all local
codes. Reference the CAPS submittal for ductwork sizes.
NOTE

Complete Rooftop Installation

The use of a duct adapter is recommended on a
downblast (DB) arrangement to align the ductwork
with the supply unit. The duct adapter is only a
guide and is not to be used as a support for the
ductwork.

3. Apply Sealant

Apply an appropriate sealant around the perimeter of
the curb
Supply Air Ductwork
and duct
(Arrangement DB only)
adapter(s)
to isolate
fan
vibration
and prevent
Sealant
water
Ductwork
penetration.

4. Install Unit

Use a crane and a
set of spreader bars
hooked to the factory
lifting lugs to lift and
center the unit on
the curb/equipment
support(s).
Use self-tapping
sheet metal screws
to fasten the unit to
the curb/equipment
support(s).
Setting Unit
4

Model MSX Make-Up Air

Installation of Roof Mounted Unit
Arrangement DBC
1. Install Curb/Equipment Support(s)

Position curb/equipment support(s) on the roof
(reference the CAPS submittal for placement of curb/
equipment support(s) in relation to the unit). Verify
that all unit supports are level, shim if necessary.
Attach curb to roof and flash into place. Attach the
equipment support(s) to the roof, remove metal cover,
flash to wooden nailer and reinstall cover.
Roof Curb

4. Apply Sealant

Apply an appropriate sealant around the perimeter of
the curb and duct adapter(s) to isolate fan vibration
and prevent water penetration.
Exhaust Duct
Installed

Exhaust
Ductwork
by Others

Supply
Ductwork
by Others

Sealant
Supply Duct with
Duct Adapter Installed

Sealing Ductwork

Metal Cover

5. Install Exhaust Fan
Equipment
Support

Roof Curb and Equipment Support

2. Install Combination Extension

Fasten exhaust fan to curb extension with selftapping sheet metal screws. Installing the exhaust fan
prior to the supply unit will allow for easier installation
of options.
Model CUBE
Exhaust Fan

Install combination extension over curb. Lag into
place using wood screws. Locate the extension so the
tall vented side is over the
Exhaust
1 inch
exhaust opening.
Inside Flange
Supply

Installing Exhaust Fan

NOTE
Combination Extension

NFPA 96 requires the exhaust fan to be hinged.

3. Install Ductwork

Good duct practices should be followed for all
ductwork. All ductwork should be installed in
accordance with SMACNA and AMCA guidelines,
NFPA 96 and any local codes. Reference the CAPS
submittal for ductwork size and location.

6. Install Exhaust Options

Install optional Greenheck hinge kit with restraining
cables and grease trap with drain connection.

Exhaust
Ductwork
by Others
Supply
Ductwork
by Others

Ductwork

NOTE
The use of a duct adapter is recommended on a
downblast (DBC) arrangement to align the ductwork
with the supply unit. The duct adapter is only a guide
and is not to be used as a support for the ductwork.
®

Model MSX Make-Up Air

7. Install Supply Unit

Use a crane and a set of spreader bars hooked to the
factory lifting lugs to lift and center the unit on the
extension/equipment support(s).
Use self-tapping sheet metal screws to fasten the unit
to the extension/equipment support(s).

Installing Supply Unit

NOTE
The use of all lifting lugs and a set of spreader bars
is mandatory when lifting unit.
NOTE
Some units come with the weatherhood attached
and Step 8 may not apply.

8. Assemble and Attach Weatherhood

The weatherhood can now be assembled and/or
attached to the unit. Detailed assembly instructions
can be found with the weatherhood. If the optional
evaporative cooling module was selected, this step
does not apply, refer to the next section, Installation of
the Optional Evaporative Cooling Module.

9. Seal Weatherhood Seam

Using an appropriate sealant, seal the seam between
the weatherhood and the unit.

Complete Combination Installation

Model MSX Make-Up Air

Installation of Evaporative Cooling
Module (optional)
NOTE
Small evaporative coolers ship attached to the base
unit and require no additional mounting.

1. Locate Equipment Support(s)

Position equipment support(s) on the roof (reference the
CAPS submittal for placement of equipment support(s)
in relation to the
Metal Cover
unit). Verify that
all unit supports
are level, shim if
necessary. Attach
Equipment
equipment support
Support
to the roof, remove
metal cover, flash
to wooden nailer
Equipment Support
and reinstall cover.

2. Apply Sealant

Apply an appropriate sealant around the airstream
opening to create an air tight seal.

4. Secure Cooling Module to Unit
Use self-tapping screws to fasten the cooling module to
the base unit along the top and down both sides. Fasten
at the top through the flanges. To fasten the sides, the
media must be removed. To remove the media, first
remove the access panel on the evaporative module
and disconnect the evaporative pump(s). The media
will now slide out. With the media removed, you can
Roof
Curbfastening points inside the evaporative
access the
side
module. With all the screws in place, reinstall the media,
reconnect the pumps and reinstall the access panel.

Securing Evaporative Module

NOTE

Sealant

When mounting the evaporative cooler, it is
important that it is level to ensure proper operation
and water drainage.

3. Set Evaporative Cooling Module

Use a crane and a set of spreader bars hooked to the
factory lifting lugs to lift and center the module on the
equipment support(s). The flange on the evaporative
cooler should overlap the flange on the unit.

Placing Evaporative Module

NOTE
The use of all lifting lugs and a set of spreader bars is
mandatory when lifting the evaporative cooling module.
®

Model MSX Make-Up Air

Installation of Electrical Wiring
important
Before connecting power to the unit, read and
understand the following instructions and wiring
diagrams. Complete wiring diagrams are attached
on the inside of the control center door(s).

1. Determine the Size of the Main Power
Lines

The unit’s nameplate states the voltage and the unit’s
MCA. The main power lines to the unit should be sized
accordingly. The nameplate is located on the outside
of the unit on the control panel side.
Voltage, Hertz, Phase

important
All wiring should be done in accordance with the
latest edition of the National Electric Code ANSI/
NFPA 70 and any local codes that may apply. In
Canada, wiring should be done in accordance with
the Canadian Electrical Code.
important
The equipment must be properly grounded. Any
wiring running through the unit in the airstream must
be protected by metal conduit, metal clad cable or
raceways.
caution
If replacement wire is required, it must have a
temperature rating of at least 105°C, except for an
energy cut-off or sensor lead wire which must be
rated to 150°C.
danger
High voltage electrical input is needed for this
equipment. This work should be performed by a
qualified electrician.
caution
Any wiring deviations may result in personal injury
or property damage. Greenheck is not responsible
for any damage to, or failure of the unit caused by
incorrect final wiring.
important
Greenheck’s standard control voltage is 24 VAC.
Control wire resistance should not exceed
0.75 ohms (approximately 285 feet total length for
14 gauge wire; 455 feet total length for 12 gauge
wire). If the resistance exceeds 0.75 ohms, an
industrial-style plug-in relay should be wired in
place of the remote switch. The relay must be
rated for at least 5 amps and have a 24 VAC coil.
Failure to comply with these guidelines may cause
motor starters to chatter or not pull in, resulting in
contactor failures and/or motor failures.

VOLTS

SUP HP

EXH HP

MCA

MOP

Unit’s Total MCA

Electrical Nameplate

2. Provide the Opening(s) for the
Electrical Connections

Phase
Electrical openings Voltage,
vary byHertz,
unit size
and arrangement
and are field supplied.

3. Connect
the Main
Power
VOLTS
HZ
PH

Connect the main power lines to the disconnect switch
EXH HP field connections to
SUP HP
and main grounding
lug(s). Torque
20 in.-lbs. MCA
MOP

4. Wire the Optional Convenience Outlet
The convenience outlet requires a separate 115 volt
power supply circuit. The circuit must include short
circuit protection which may need to be supplied by
others.

5. Wire the Optional Accessories

Reference the Ladder Diagram on the inside of the
control center door for correct wiring of the following
accessories:
• Blower Switch
• Heat Switch
• Indicating Lights
• Dirty Filter Indicator

• TSCP
• KSCP

NOTE
TSCP has number-to-number wiring.

6. Wire the Optional Evaporative Cooler

Reference the Ladder Diagram on the inside of the
control center door for correct wiring of the pump and
the optional auto-drain and flush.
NOTE
Large evaporative coolers may require a separate
power supply.

Model MSX Make-Up Air

Installation of Electric Heater
(optional)
Warning
Electrical Shock Hazard! Disconnect all power
sources before doing any work on the unit.

Sizing of Supply Conductors

The required minimum size of supply conductors
is marked at the field wiring terminals within the
heater control box or reference the Supply Wire Size
table included in this section. The wire gauges are
calculated for 125% of the heater line current as
required by the National Electric Code, Article 424-3(b)
based on conductor insulation rated for 75°C (167°F).

General:
The requirements and practices described below
are based on the National Electric Code (NEC) and
The Space Heating Standard of the Underwriters
Laboratories Inc. (UL). Although UL requirements
are uniform throughout the country, local electrical
codes may deviate from the National Electrical Code.
Therefore, local inspection authorities should be
consulted regarding local requirements.

Electrical Wiring Instructions:
1. Use the wiring diagram supplied with the heater
as a guide in correlating field wiring with the
heater internal wiring.
2. All field wiring to the heater must meet the
requirements of the National Electric Code and
any other applicable local or state codes.
3. Wiring to the heater must be rated for 75°C
(167°F) minimum.
4. The fan is interlocked by the factory to the
control circuit so the electric heater will not
operate unless the fan is on.
5. If heater does not have a built-in disconnect
switch or main circuit breaker, install a remote
disconnect (furnished by others) in accordance
with the National Electric Code, Article 424-65.

Calculation of Line Currents (amps):
watts
Single Phase Current =
volts
EXAMPLE: 5 kW, 208 volt
5000 watts
= 24 amps
208 volts
Three Phase Current =

watts
volts x 1.73

EXAMPLE: 14.4 kW, 208 volt
14400 watts
14400
=
= 40 amps
208 volts x 1.73
360

Supply Wire Size

(Not more than six conductors in Single Conduit 1)
AWG or
MCM

Copper 3

AWG or
MCM

Max. Heater
Line Current 2
Copper 3

0000

184

250

204

300

228

350

248

400

268

500

304

600

336

700

368

104

750

380

120

800

392

140

900

416

000

160

1000

436

1 For 7-24 conductors in raceway or cable, reduce allowable

heater line currents to 871/2% of those shown above.

2 Based on 30°C. (86°F.) ambient temperature, for higher

ambient temperature see National Electric Code table
310‑16 and 310-18 Note 13.

3 Based on 80% of ratings in the National Electric Code

table 310-16 for 75°C insulation.

Effect of Low Voltage on Wattage and
British Thermal Unit (BTU)

The heating elements may be used on voltages
lower than the design voltage of the heater, however,
the wattage and BTU output will be reduced to the
percentages listed in the table below.

De-rated Wattage For Low Voltage
% of
% of
Heater Line
Heater Heater Line
Heater
Voltage Voltage Wattage Voltage Voltage Wattage
and BTU
and BTU
480
277
240

Max. Heater
Line Current 2

460

440

265

254

230

220

208

200

208
120

200

190

115

110

Model MSX Make-Up Air

Installation Evaporative Cooler
Piping (optional)
Evaporative Cooling with Recirculating Pump

Evaporative Cooling with Auto Drain and Fill

Supply
Line

VALVE A
Supply Solenoid
(Normally Closed)

Supply
Line Valve
(Normally
Closed)

Drain Line Valve
(Normally Open)

Overflow
Drain Line

Sump Drain
VALVE C
Sump Drain Solenoid
(Normally Open)
VALVE B
Supply Line Drain Solenoid
(Normally Open)

Trap

Recirculating Evaporative Piping

All supply solenoids, valves and all traps must be below
the roof line or be otherwise protected from freezing.
important
The supply line should be of adequate size and
pressure to resupply the amount of water lost due to
bleed-off and evaporation. The drain line should be
the same size or larger than the supply line.
caution
Provisions must be taken to prevent damage to the
evaporative cooling section during freezing conditions.
The sump, drain lines and supply lines must be
drained prior to freezing conditions or an alternate
method must be used to protect the lines and media.

1. Install the Water Supply Line

2. Install the Drain Line

Connect an unobstructed drain line to the drain and
overflow connections on the evaporative cooler. A
manual shut off valve (by others) is required for the
evaporative cooler
drain line.
6 in. min.

Drain Trap

3. Check/Adjust Water Level

Trap
Drain Line

Auto Drain & Fill Evaporative Piping

important

A trap should be
used to prevent
sewer gas from
being drawn into
the unit.

Supply
Line

Sump Overflow

6 in. min.

Important
The supply line should be of adequate size and
pressure to resupply the amount of water lost due to
bleed-off and evaporation. The drain line should be
the same size or larger than the supply line.
caution
All solenoids valves and traps must be installed below
the roof to protect the supply water line from freezing.
If they cannot be installed below the roof, an alternative
method must be used to protect the lines from freezing.
Important
The supply solenoid (Valve A) is NOT the same as
the drain solenoids (Valve B and Valve C). Make sure
to use the proper solenoid for each location. Check
your local code requirements for proper installation
of this type of system.
Auto Drain & Flush Valves
(When provided by Greenheck)
Assembly
Number

GFC
ASCO
Solenoid De-Energized
Part
Part
Diameter Qty.
Type
Position
Number Number
Supply

Closed

1/2 inch
(12.7 mm)

852178 461263 8262G262

Supply
Line
Drain

Open

1/4 inch
(6.35 mm)

461264 8210G35

Sump
Drain

Open

3/4 inch
1
(19.05 mm)

461262 8210G2

Part numbers subject to change.

Check the water level in the sump tank. The water
level should be above the pump intake and below the
overflow. Adjust the float as needed to achieve the
proper water level.
10 Model MSX Make-Up Air

Evaporative Cooling with Auto Drain and Fill
continued

1. Install the Water Supply Line

Supply line opening requirements vary by unit size
and arrangement and are field supplied. Connect the
water supply line to the float valve through the supply
line opening in the evaporative cooling unit. Install the
1/2 in. normally closed solenoid (Valve A) in the supply
line. Install the 1/4 in. normally open solenoid (Valve
B) between the supply line and the drain line. Refer
to Auto Drain & Fill Evaporative Piping drawing on
previous page.

2. Install the Drain Line

Connect an unobstructed drain line to the sump drain
overflow connection. Install the 3/4 in. normally open
solenoid (Valve C)
between the sump
drain connection
and the drain line.
6 in. min.
A trap should be
used to prevent
6 in. min.
sewer gas from
Drain Trap
being drawn into
the unit.

3. Check/Adjust Water Level

Check the water level in the sump tank. The water
level should be above the pump intake and below the
overflow. Adjust the float as needed to achieve the
proper water level.

Model MSX Make-Up Air 11

Installation of Water WizardTM (optional)

To Media
Pressure
Gauge

Evaporative Cooling with the Water Wizard™
Sump Drain

Note
The following instructions are provided for evaporative
coolers equipped with the Water Wizard™ only.
Additional instructions are provided for evaporative
coolers equipped with the auto-drain and fill or
bleed‑off.
Warning

GFC
Assembly
Part
Number
No.

MSX H12/H22

DeASCO Solenoid
Energized Diameter Qty.
Part No. Type
Position

461262 8210G2 Supply Closed
852370

Supply
Line
Drain

1/2 inch
1
(12.7 mm)
1/2 inch
1
(12.7 mm)

MSX - H32
(<9000 cfm)

383086 8210G34

MSX - H32
(≥9000 cfm)

383088 8210G9 Supply Closed

3/4 inch
1
(19.05 mm)

Supply
383086 8210G34 Line
Drain

1/2 inch
1
(12.7 mm)

MSX-H35,
H38, H42

852371

Open

Supply Solenoid
(Normally Closed)

Roof
Line

Supply Line Drain Solenoid
(Normally Open)

Field
Installed

Water Wizard™ Installation

3. Wire the Solenoid(s)

Wire the supply line solenoid and drain solenoid as
shown on the unit’s wiring diagram in the control
center.

Water Wizard™ Valves
(When provided by Greenheck)
Unit
Model

Manual Supply
Valve

Trap

Disconnect and lock-out all power and gas before
performing any maintenance or service to the unit.
Failure to do so could result in serious injury or
death and damage to equipment.

Factory
Installed

4. Wire the Temperature Sensor

If the evaporative cooler shipped separate from the
unit, the temperature sensor must be wired. The
sensor wire is bundled inside the discharge end of the
evaporative cooler. Wire the sensor wire to terminals
AI2 and AIC on the terminal strip in the unit’s control
center.
Note
The Water Wizard™ start-up must be completed for
proper performance.

Part numbers subject to change.

1. Install Normally Closed Supply Line/
Solenoid

Connect the water supply line to the manual supply
valve in the unit. Install the supply solenoid in the
supply line, upstream of the manual supply valve and
below the roof line.

2. Install Normally Open Drain Line/
Solenoid

Connect the drain line to the supply line between the
manual supply valve and the supply solenoid. Install a
drain solenoid in the drain line, below the roof line. A
trap should be installed in the drain line.
Note
Solenoid(s) may be provided by Greenheck (if
ordered) or by others.
Caution
Any wiring deviations may result in personal injury
or property damage. Greenheck is not responsible
for any damage to, or failure of the unit caused by
incorrect final wiring.

12 Model MSX Make-Up Air

Installation of Direct Expansion (DX)
Coil Piping (optional)
Important
Guidelines for the installation of direct expansion
cooling coils have been provided to insure proper
performance and longevity of the coils. These are
general guidelines that may have to be tailored
to meet the specific requirements of any one job.
As always, a qualified party or individual should
perform the installation and maintenance of any coil.
Protective equipment such as safety glasses, steel
toe boots and gloves are recommended during the
installation and maintenance of the coil.
Important
All field brazing and welding should be performed
using high quality materials and an inert gas purge
(such as nitrogen) to reduce oxidation of the internal
surface of the coil.

Note
If a hot gas bypass kit was provided by others, refer
to the manufacturer’s instructions.

3. Install Suction Line

Install suction line(s) from the compressor to the
suction connection(s) which are stubbed through the
side of the cabinet.

4. Install the Liquid Line and Thermal
Expansion Valve (TEV) (by others)

Liquid line openings vary by coil size and
circuiting and are field supplied. Follow the TEV
recommendations for installation to avoid damaging
the valve. If the valve is externally equalized, use a
tubing cutter to cut off the plugged end of the factory
installed equalizer line. Use a de-burring tool to
remove any loose metal from the equalizer line and
attach it to the TEV. If the valve is internally equalized,
the factory installed equalizer line can be left as is.

Important
All field piping must be self-supporting and flexible
enough to allow for the thermal expansion of the coil.

Coil

Suction Header
Distributor

Liquid Line

Equalizer Line
Nozzle

1. Locate the Distributor(s) by Removing
the Distributor Access Panel

Thermal
Expansion
Valve (by others)

Suction Line
Remote Sensing Bulb

Straps
Suction Connection

General Installation

5. Mount the Remote Sensing Bulb
(by others)

Distributor Access Panel

The expansion valve’s remote sensing bulb should be
securely strapped to the horizontal run of the suction
line at the 3 or 9 o’clock position and insulated.

6. Check Coil Piping for Leaks
Thermal
(by others)
(by others)

Installation with Hot Gas Bypass

2. Verify Nozzle Placement
Inspect the refrigerant
distributor and verify
that the nozzle is in
place. The nozzle is
generally held in place
by a retaining ring or is
an integral part of
the distributor itself.
®

Retainer
Ring

Nozzle

Pressurize the coil to 100 psig with dry nitrogen or
other suitable gas. The coil should be left pressurized
for a minimum of 10 minutes. If the coil holds the
pressure, the hook-up can be considered leak free.
If the pressure drops by 5 psig or less, re-pressurize
the coil and wait another 10 minutes. If the pressure
drops again, there is likely one or more small leaks
which should be located and repaired. Pressure losses
greater than 5 psig indicate a large leak that should be
isolated and repaired.

7. Evacuate and Charge the Coil

Distributor

Nozzle Placement

Use a vacuum pump to evacuate the coil and any
interconnecting piping that has been open to the
atmosphere. Measure the vacuum in the piping using
a micron gauge located as far from the pump as
possible. Evacuate the coil to 500 microns or less,
and then close the valve between the pump and the
system. If the vacuum holds to 500 microns or less
Model MSX Make-Up Air 13

for one minute, the system is ready to be charged or
refrigerant in another portion of the system can be
opened to the coil. A steady rise in microns would
indicate that moisture is still present and that the coil
should be further vacuumed until the moisture has
been removed.
Note
Failure to obtain a high vacuum indicates a great
deal of moisture or a small leak. Break the vacuum
with a charge of dry nitrogen or other suitable
gas and recheck for leaks. If no leaks are found,
continue vacuuming the coil until the desired
vacuum is reached.

8. Install the Drain Line
Connect an
unobstructed drain
line to the drain
pan. A trap should
be used to prevent
sewer gas from being
drawn into the unit.

6 in. min.

Drain Trap

Important
All traps must be installed below the roof line or be
otherwise protected from freezing.

Installation of Chilled Water Coil
Piping (optional)
Important
Guidelines for the installation of the cooling coil
have been provided to insure proper performance
of the coils and their longevity. These are general
guidelines that may have to be tailored to meet the
specific requirements of any one job. As always,
a qualified party or individual should perform the
installation and maintenance of the coil. Protective
equipment such as safety glasses, steel toe boots
and gloves are recommended during the installation
and maintenance of the coil.
When installing couplings, do not apply undue
stress to the connection. Use a backup pipe
wrench to avoid breaking the weld between the coil
connection and the header.
All field piping must be self-supporting. System
piping should be flexible enough to allow for the
thermal expansion and contraction of the coil.

1. Verify Coil Hand Designation

Check the coil hand
Hot Return
designation to ensure that
Connection
it matches the system.
Coils are generally
Entering Air
Leaving Air
plumbed with the supply
connection located on
Cold Supply
Connection
the bottom of the leaving
air-side of the coil and the
return connection at the top of the entering air-side
of the coil. This arrangement provides a counter flow
heat exchanger and positive coil drainage.

2. Check the Coil for Leaks

Pressurize the coil to 100 psig with dry nitrogen or
other suitable gas. The coil should be left pressurized
for a minimum of 10 minutes. If the coil holds the
pressure, the hook-up can be considered leak free.
If the pressure drops by 5 psig or less, re-pressurize
the coil and wait another 10 minutes. If the pressure
drops again there is likely one or more small leaks
which should be located and repaired. Pressure losses
greater than 5 psig indicate a large leak that should be
isolated and repaired.

3. Connect the Supply and Return Lines
Connect the supply and return lines as shown above.

4. Install the Drain Line
Connect an unobstructed
drain line to the drain pan.
A trap should be installed
to prevent sewer gas from
being drawn into the unit.

6 in. min.

Drain
Trap

6 in. min.

Important
All traps must be installed below the roof line or be
otherwise protected from freezing.
14 Model MSX Make-Up Air

Installation of Building Pressure
Control (optional)
1. Mount Pressure Tap

Using the factory provided bracket, mount the
pressure tap to the
outside of the unit.
Choose a location
out of the prevailing
winds and away from
supply or exhaust
fans to assure
accurate readings.

2. Run Pressure Tap Lines

Run a pressure tap line from the pressure tap on the
outside of the unit to the low pressure tap on the back
of the photohelic gauge. Run a second pressure tap
line from the high pressure tap on the back of the
photohelic gauge to the space. Fifty feet of tubing is
supplied with the unit.

High Pressure
Tap
to Space

Factory
Wiring
Low Pressure
Tap
to Outside

Connections for Photohelic Gauge

3. Set the Building Pressure

The pressure gauge is used to set the desired building
pressure. The pressure is set by adjusting the knobs
for the upper and lower pressure limits. Typical
settings are 0.0 inch wc for the lower and 0.10 inch wc
for the upper pressure setting.
Pressure Indicating
Needle

Pressure Setting
Needles

Pressure Setting Knobs

Typical Photohelic Gauge Settings

Model MSX Make-Up Air 15

Start-Up - Blower

Rotate the fan wheel by hand and make sure no parts
are rubbing. Check the V-belt drive for proper alignment
and tension (a guide for proper belt tension and
alignment is provided in the Belt Maintenance section).
Check fasteners, set screws and locking collars on the
fan, bearings, drive, motor base, and accessories for
tightness.
warning
Disconnect and lock-out all power and gas before
performing any maintenance or service to the unit.
Failure to due so could result in serious injury or
death and damage to equipment.
SPECIAL EQUIPMENT REQUIRED
Required and recommended tools. Equivalent
products may be used.
Manufacturer: Fluke
Model: 177
Phone: 1-800-44-FLUKE
www.fluke.com

Voltage &
Amperage
Meter

Manufacturer: Fluke
Model: 50
Phone: 1-800-44-FLUKE
www.fluke.com
Manufacturer: Fluke
Model: 116
Phone: 1-800-44-FLUKE
www.fluke.com
Manufacturer: Dwyer
Model:
Slack Tube
Phone: 1-219-897-8000
www.dwyer-inst.com
Manufacturer: Monarch
Voltage, Hertz, Phase
Model:
Pocket Tach 100
Phone: 1-800-999-3390
www.monarchinstrument.com

Thermometer

Micro Amp
Meter
U-Tube
Manometer

Tachometer
VOLTS
SUP HP

tio

Blower
Housing

Blower Rotation

Note
To reverse the rotation on three phase units,
disconnect and lock-out the power, then
interchange any two power leads.
Note
To reverse the rotation on single phase units,
disconnect and lock-out the power, then rewire the
motor per the manufacturer’s instructions.
Important
If the blower is rotating in the wrong direction, the
unit will move some air, but will not perform as
designed. Be sure to perform a visual inspection to
guarantee the correct blower rotation.

3. Check for Vibration

Check for unusual noise, vibration or overheating of
the bearings. Reference the Troubleshooting section
for corrective actions.
Important
Excessive vibration may be experienced during
the initial start-up. Left unchecked, it can cause a
multitude of problems including structural and/or
component failure.
Important
Generally, fan vibration and noise is transmitted
to other parts of the building by the ductwork. To
minimize this undesirable effect, the use of heavy
canvas duct connectors is recommended.

4. Motor Check

EXH HP
Warning

MCA
Check the housing,
blower,MOP
and ductwork for any
foreign objects before running the blower.

Unit’s Total MCA

1. Check the Voltage

Before starting the unit, compare the supplied voltage,
hertz, and phase with the unit and motor’s nameplate
information.
Voltage, Hertz, Phase

VOLTS

Open the blower access door
and run the blower momentarily
to determine the rotation.
Arrows are placed on the
blower scroll to indicate the
proper direction or reference
the example shown to the right.

Refer to the Start-Up Checklist in the Reference
section before proceeding further!
Pre Start-Up Check

2. Check the Blower Rotation

Measure the motor’s voltage, amps and RPM.
Compare to the specifications. Motor amps can be
reduced by lowering the motor RPM or increasing
system static pressure.
Important
Additional starters and overloads may be provided
in the make-up air control center for optional
exhaust blowers. Any additional overloads must be
checked for proper voltage, amps and RPMs.

SUP HP

EXH HP

MCA

MOP

Electrical Nameplate
16 Model MSX Make-Up Air

5. Air Volume Measurement & Check

Measure the unit’s air volume (cfm) and compare it with
it’s rated air volume. If the measured air volume is off,
adjust the fan’s RPM by changing/adjusting the drive.
Note
The most accurate way to measure the air volume is
by using a pitot traverse method downstream of the
blower. Other methods can be used but should be
proven and accurate.
Important
Changing the air volume can significantly increase
the motor’s amps. If the air volume is changed,
the motor’s amps must be checked to prevent
overloading the motor.
Note
To ensure accuracy, the dampers are to be open
when measuring the air volume.

6. Set-Up Optional Components

Adjust the settings on the optional components. See
the Control Center Layout in the Reference section for
location of optional components.
• Heating Inlet Air Sensor
Typical setting: 60-70°F (15-21°C)
• Cooling Inlet Air Sensor
Typical setting: 75°F (24°C)
• Building Freeze Protection
Typical setting: 5 minutes; 45°F (7°C)
• Dirty Filter Gauge
Typical setting: Settings vary greatly for each unit.
(see Reference section for adjusting information)

Model MSX Make-Up Air 17

Start-Up - Electric Heater (optional)
Refer to the Start-Up Checklist in the Reference
section before proceeding further!
Pre Start-Up Check

Check all electrical connections. Tighten any loose
connection to all components including contactors,
heating elements and main power lugs.
warning
Disconnect and lock-out all power before
performing any maintenance or service to the unit.
Failure to due so could result in serious injury or
death and damage to equipment.

1. Check the Voltage

Before starting the heater, compare the supplied
voltage, hertz, and phase with the heater’s nameplate
information.

2. Airflow Interlock

With the supply fan on, verify the electric heater’s
airflow interlock (DDS) is made.

3. Set the Unit’s Operating Temperature
Set the operating temperature by adjusting the
discharge temperature selector. Typical settings are
65-70°F (18-21°C).
note
If the heater is equipped with an optional inlet
air sensor the heater will not energize unless the
outdoor air temperature is less than the inlet air
sensor’s set point.

18 Model MSX Make-Up Air

Start-Up - Evaporative Cooling
Recirculating (optional)

8. Put the Unit into Service

Remove the jumper, and energize the blower(s). Verify
proper operation.

1. Check the Installation

The media may have been removed during installation,
so its orientation
45º
should be double
checked. The
media should
be installed with Entering Air
Leaving Air
the steeper flute
angle sloping
down towards
15º
the entering air
Media Orientation
side.

important
Check the media for minerals after two weeks of
service and adjust the bleed-off rate accordingly.
Bleed-Off
Valve

Pump
Filter

Supply
Connection

Float
Valve

Threaded Float
Adjustment

Overflow

Verify that the stainless steel caps and distribution
headers are in place. The headers should be located
over the media towards the entering air side. The caps
should be placed over the headers.

2. Check the Pump Filter

Check that the pump filter is around the pump inlet.

3. Fill the Sump and Adjust the Float

Evaporative Cooler Set-Up

Turn on the water supply and allow the sump tank to
fill. Adjust the float valve to shut-off the water supply
when the sump is filled to within 1 inch of the bottom
of the overflow.

4. Break-in the Media

Open the bleed-off valve completely and saturate
the media with the blower(s) off for no less than 20
minutes.

Temperature
Setting
t2 settings

t1 settings

Note
A jumper will need to be installed in the control
center to power the evaporative pumps with the
blower(s) off. Reference the unit’s ladder diagram to
determine proper terminals.

Evaporative Freeze
Protection

Evaporative
Timer

5. Check the Flow Rate

The pumps should provide enough water to saturate
the media in 45 to 60 seconds. Consult the factory, if
adequate flow is not achieved.

6. Adjust the Water Bleed-Off Rate

The water bleed-off rate is dependent on the water’s
mineral content. The bleed-off should be adjusted
based on the media’s mineral deposits after two
weeks of service.

7. Set the Optional Auto Drain and Fill

Set the auto drain, fill timer and temperature settings.
Timer settings are: t1: 1.0, 10min

t2: 0.4, 60h
Temperature is typically set to 45°F (7°C)

Model MSX Make-Up Air 19

Start-Up - Water Wizard™ (optional)
L1

Function Key

Up Key

5. Check Media

Start the cooling cycle and check the media after one
hour of operation. If the media is continuously dry or if
too much water is draining from the sump tank, refer
to Troubleshooting, Water Wizard™.
NOTE

Enter Key

Down Key
Water Wizard™ User Interface
Key Function Description

Steps 6 through 8 are provided to adjust the
minimum cooling temperature. The minimum cooling
is preset to the factory recommended 75°F (24°C).
Only adjust if needed.

1. Open the Solenoid

NOTE

Confirm that the manual water supply valve
is closed. Press and hold the Function Button
for one second. L3 will begin blinking (short on, long
off), indicating that Flow Test Mode is active and the
supply solenoid is open.

2. Set the Water Pressure

With the solenoid open, set the supply water
pressure to the correct setting (see table below).
Use the manual supply valve to adjust the supply
pressure. A pressure gauge is provided between the
manual supply valve and the media.
warning
Opening the manual supply valve will allow water
to pass to the media. Be sure the sump is safely
draining before opening the manual supply valve.
NOTE
The manual supply valve ships closed and must be
adjusted for proper performance.
Recommended Water Pressure Chart
Housing
Size
MSX-H12
MSX-H22
MSX-H32
MSX-H35
MSX-H38
MSX-H42

Media Width
(inches)
30
433⁄4
60
66
96*
120*
180*
216*

Water Pressure
(in. wc)
20
36
61
72
42
61
37
51

*Multiple media sections. Values represent total media width.

NOTE
The recommended water pressure is based on
media width. Refer to the table provided for proper
water pressure settings.

The inlet air sensor function overrides and shuts
down the evaporative cooler if the outside
temperature falls below the minimum cooling
temperature.

6. Enter Program Mode
Press and hold
the Enter Key
for three seconds. The
display will read “Pro”
when Program Mode is
active.

Program Display

7. Adjust the Minimum Cooling
Temperature

While in the
Program Menu,
use the Up and
Down Keys to
navigate the
Menu Options
Minimum Cooling
until “toF” is
Temperature Display
displayed. Press the
Enter Key to access the selected Menu Option setting.
Use the Up and Down Keys to adjust the Minimum
Cooling Temperature as needed. Press the Enter Key
to save the Minimum Cooling Temperature setting and
return to the Program Menu.
NOTE
The enter key must be pressed to save the new
minimum cooling temperature.

8. Exit Program Mode

After 15 seconds of idle time the controller will exit
Program Mode.

3. Break-in Media

Leave the supply solenoid open to saturate and
break‑in media for 20 minutes with the blower off.

4. Close Solenoid

With the pressure set, press the Function Key
for one second to deactivate Flow Test Mode
and allow the supply solenoid to close.
20 Model MSX Make-Up Air

NOTE
The Freeze Temperature is preset to the factory
recommended 45°F. Steps 9-11 should only be
completed if the Freeze Temperature needs adjustment.
NOTE
The Freeze Temperature is the temperature at which the
supply solenoid closes and the drain solenoid opens
to drain the supply line, preventing possible freeze
damage. A drain solenoid is required for this option.

9. Enter Program Mode
Press and hold
the Enter Key
for three seconds. The
display will read “Pro”
when Program Mode is
active.

Program Display

10. Adjust the Freeze Temperature

While in Program Mode, use the Up and Down
Keys to navigate
through the Menu
Options until
“Frt” is displayed.
Press the Enter
Key to access the
Freeze Temperature
selected Menu Option
Display
setting.
Use the Up and Down Keys to adjust the Freeze
Temperature setting as needed. Press the Enter Key to
set the Freeze Temperature and return to the Program
Menu.
NOTE
The enter key must be pressed to save the new
freeze temperature.

11. Exit Program Mode

After 15 seconds of idle time the controller will exit
Program Mode.

Model MSX Make-Up Air 21

Check Operation - VAV Units
(optional)

Building Pressure Control —
a variable frequency drive is
controlled according to input
from a pressure sensing device.

NOTE
Blower Start-Up, Steps 1-5 should be performed
before the blower is run.
NOTE
For maintenance issues associated with variable
frequency drives, consult the drive’s manual
supplied with the unit. The drives are programmed
at the factory and should not need any adjustment
during installation and start-up. For kitchen
applications, the drive may be located in the kitchen
or in the unit.

Variable Volume Operation

The variable volume option is recommended when
a building’s exhaust volume may vary. This option
enables the make-up air volume to track with the
exhaust volume, providing only the amount of makeup air required. Control strategies include 2-speed and
modulating blowers. Before the unit is left in service,
the variable volume control system should be tested.

2-Speed
A variable frequency drive (VFD) is used to control
air volumes. The VFD can be switched to low or high
speed from a remote control panel. Turn the fan speed
switch on the remote control panel to each position
and confirm that the fan speed adjusts accordingly.

Modulating
Potentiometer Control — a variable frequency drive
is controlled by input from a remote
speed selector (potentiometer).
This unit allows easy manual
adjustment of make-up air
volumes. To test potentiometer
operation, turn the potentiometer
to the two extremes. With variable
volume, make sure the fan goes to
maximum and minimum speed.

BLOWER
EXHAUST
(OPTIONAL)
SUPPLY

MAIN VALVES
HEAT

Turn both knobs to the upper
most pressure setting. You may
have to remove the outdoor
pressure tap tubing. VAV systems
should go to maximum speed.
Set both knobs at the lowest
setting and the VAV systems
should go to minimum speed.
Reset the correct pressure limits
before starting the unit.
This picture depicts a
typical photohelic setting.
Typical settings are 0.0 inch
wc for the lower pressure
setting and 0.10 inch wc for
the upper pressure setting.
The needle indicates a
negative building pressure.
During correct operation,
the indicating needle will
remain between or near the
setting needles.

DIRTY FILTERS
75

(OPTIONAL)

85
90

PHOTOHELIC

GREENHECK

With Maxitrol 44 Room Thermostat

Building
Pressure Control

Pressure Indicating
Needle

Pressure Setting
Needles

Pressure Setting Knobs

Photohelic Gauge

External Signal — a variable frequency drive is
controlled according to input from an external 2-10
VDC or 4-20 mA signal (by others).
A 2 VDC or 4 mA signal will send the blower to low
speed. The blower will go to maximum speed with a
10 VDC or 20 mA signal.
Variable Kitchen Control — a variable frequency
drive is controlled by input from a remote speed
control. This unit allows automatic adjustment of
make-up air volumes based on varying cooking loads.

BLOWER

EXHAUST

(OPTIONAL)

SUPPLY

MAIN VALVES

HEAT

DIRTY FILTERS

When the potentiometer is at 0, the
fan speed will be at its minimum.
When the potentiometer is at 100,
the fan will be at its maximum
speed.

22 Model MSX Make-Up Air

(OPTIONAL)

GREENHECK

With Maxitrol 44 Room Thermostat
Potentiometer
Control

Check Operation - Recirculating
Units (optional)
NOTE
Blower Start-Up, steps 1-5 should be performed
before the blower is run.

Recirculation Operation

The recirculation operation option is recommended
when the ventilation equipment provides the primary
source of heating for the space. Recirculation can
vary from 100% return air to 100% outside air. Control
strategies include 2-position and modulating dampers.
Before the unit is left in service, the recirculation
control system should be tested.

A 2-position spring return actuator is used to control
the return air amounts. The damper moves from open
to closed. If power is cut to the
unit, the outdoor air damper will
fail to close.
BLOWER

(OPTIONAL)

SUPPLY

MAIN VALVES

HEAT

Turn the recirculating switch
on the remote control panel to
each position and confirm that
the return air damper adjusts
accordingly. The damper actuator
may take a few minutes to open
or close.

RECIRCULATION

DIRTY FILTERS
75

(OPTIONAL)

GREENHECK

With Maxitrol 44 Room Thermostat

2-Position
Damper Control

Modulating
Potentiometer Control — a modulating spring return
actuator is used to control the return air amounts. The
return air damper modulates from fully open to fully
closed based on a signal from a remote potentiometer.
To test potentiometer operation,
turn the potentiometer to the two
extremes. Confirm that the return
air damper fully opens and fully
closes. When the potentiometer
is at 0, the return air damper will
open. When the potentiometer is
at 100, the return air damper will
close. The damper actuator may
take a few minutes to open or
close.

Turn both knobs to the upper
most pressure setting. You may
have to remove the outdoor
pressure tap tubing. The return air
damper should close.

BLOWER
EXHAUST
(OPTIONAL)
SUPPLY

MAIN VALVES
HEAT

DIRTY FILTERS
75

(OPTIONAL)

85
90

PHOTOHELIC

GREENHECK

With Maxitrol 44 Room Thermostat

Building
Pressure Control

Set both knobs at the lowest setting and the damper
should open. It may take one to two minutes for the
damper to reach the desired position.
Reset the correct pressure limits before starting the
unit.

2-Position Damper

EXHAUST

Building Pressure Control — a
modulating spring return actuator
is used to control the return air
amounts. The return air damper
modulates from fully open to fully
closed based on a signal from a
remote pressure sensing device.

This picture shows a typical
photohelic setting. Typical
settings are 0.0 inch wc
for the lower and 0.10 inch
wc for the upper pressure
setting. The needle in this
photo indicates a negative
building pressure. During
correct operation, the
indicating needle will remain
between or near the setting
needles.

Pressure Indicating
Needle

Pressure Setting
Needles

Pressure Setting Knobs

Photohelic Gauge

External Signal — a modulating spring return
actuator is used to control the return air amounts.
Return air damper modulates from fully open to fully
closed based on an external 2-10 VDC or 4-20 mA
signal (by others).
The return air damper will close with a 10 VDC or
20 mA signal. The return air damper should open with
a 2 VDC or 4mA signal. The damper actuator may take
a few minutes to open or close.

BLOWER
EXHAUST
(OPTIONAL)
SUPPLY

MAIN VALVES
HEAT

DIRTY FILTERS
75
80

70
65
60

85
90

(OPTIONAL)

GREENHECK

With Maxitrol 44 Room Thermostat
Potentiometer
Control

Model MSX Make-Up Air 23

Operation - Electrical
Electrical Sequence
1. Exhaust Fan Contact (S1) Closed
(optional)

• Power passes through N.C. contact on exhaust
fan overload (ST2 OL), which is closed if
exhaust fan (M2) has not overloaded
• Power passes to exhaust fan starter (ST2)
• N.O. contact on exhaust fan starter (ST2) is
energized and closed
• Power passes to exhaust fan
• Exhaust fan (M2) starts

2. Supply Fan Contact (S2) Closed

• Power passes through N.C. field supplied fire
contact (FSC)
• Power passes through optional N.O. contact on
exhaust fan starter (ST2), which is closed when
the optional exhaust starter (ST2) is activated
• Power passes through N.C. contact on supply
starter overload (ST1 OL), which is closed if the
supply fan has not overloaded
• Power passes through N.C. contact on optional
freeze protection timer (RT4) which remains
closed if the temperature has remained above
the set point
• Power passes to and energizes optional inlet
damper (D1), which opens
• Power passes through optional N.O. damper
limit switch (DL1), which is energized and
closed when the optional inlet damper is open.
It may take several minutes for the damper to
fully open and for the damper limit switch to
close
• Power passes to and energizes fan relay (RF)
• Power passes through N.O. contact on fan relay
(RF), which closes when the fan relay (RF) is
energized
• Power passes to and energizes supply fan
starter (ST1)
• N.O. contact on supply fan starter (ST1) is
energized and closed
• Supply fan (M1) starts

differential switch (PDS), which closes when
proper airflow is achieved
• Power passes through N.C. automatic and
manual reset temperature cutouts (A and
M), which remain closed if the maximum
temperature has not been reached
• Power passes to and energizes operating
contactor relay (C1)
• Power passes through N.O. contacts on
operating contactor (C1), which is closed
• Electric heater modulates/stages to maintain
temperature set point

4. Evaporative Cooling Contact (S4)
Closed* (optional)

• N.O. contact on fan relay (RF) is energized and
closed
• Power passes through N.O. contact on optional
inlet air sensor (TS4), which is energized and
closed if the inlet air temperature is above the
set point
• Power passes to and energizes cool relay (RC)
• N.O. contact on cool relay (RC) is energized and
closed
• Power passes to optional evaporative cooling
pump (P1)

*If DX or chilled water coils are used rather than an evaporative
cooler, the cooling sequence of operation will depend on the coil
controls. Cooling coil controls are supplied by others.

3. Electric Heat Contact (S4) Closed
(optional)

• Power passes through N.O. contact on fan relay
(RF), which is energized and closed
• Power passes through N.C. contact on optional
inlet air sensor (TS4), which is closed if the inlet
air temperature is below the set point
• Power passes to and energizes heat relay (RH)
• Power passes through N.O. contact on heat
relay (RH), which closes when the heat relay
(RH) is energized
• Power passes through N.O. contact on pressure

24 Model MSX Make-Up Air

Operation - Water Wizard™ (optional)
L1

Function Key

Up Key

Dry Bulb Temperature

The dry bulb temperature is visible on the home
screen. If a number is not visible, wait 15 seconds
and use the Up and Down Keys until a number is
displayed.

Wet Bulb Temperature
Enter Key

Down Key
Water Wizard™ User Interface
Key Function Description

Drain Mode

Drain Mode locks open the drain solenoid and drains
the supply line between the supply solenoid and
the media. To activate Drain Mode simultaneously,
press the Function and Enter Keys (L2 will light). To
deactivate Drain Mode and unlock the drain solenoid,
simultaneously press the Function and Enter Keys
again.

Flow Test Mode

Activating Flow Test Mode opens the supply solenoid
and allows water to pass to the manual supply
valve. To activate Flow Test Mode, press and hold
the Function Key for one second (L3 will flash). To
deactivate Flow Test Mode and allow the supply
solenoid to close, press and hold the Function Key
again for one second.

To view the Wet Bulb Temperature, simultaneously
press and hold the Up and Down Keys.

Indicating Lights

Three indicating lights are located across the top
of the display to indicate the status of the Water
Wizard™.
Light Status
Indicating
Light

Off

Blinking
(Long on,
Short Off)

Blinking
(Short on,
Long Off)

Call for
cooling

No call
for
cooling

Call for
cooling.
Outdoor
temperature
lockout.

N/A

Drain
solenoid
open

Drain
solenoid
closed

N/A

Supply
solenoid
open.
(Drain
solenoid
closed).

Cooling
on

Cooling
off

Supply
solenoid
locked
closed

Flow test
mode active

Caution
The sump drain line must be clear and draining to a
safe location before using Flow Test Mode.
Caution
Be aware of the water level in the sump tank at all
times when using the Flow Test Mode.

Program Mode

Program Mode allows the user to view the Program
Menu and edit the factory default settings. To access
Program Mode and view the Program Menu press and
hold the Enter key for three seconds. While viewing
the Program Menu press the Up and Down keys to
scroll through the Menu Options. To view the setting
of the selected Menu Option, press the Enter key.
To edit the setting, press the Up or Down key while
viewing the setting. To save the setting and return to
the Program Menu, press the Enter key. To return to
the Program Menu without saving the change, wait
10 seconds. To exit Program Mode from the Program
Menu, wait 10 seconds.
warning
Changing the default settings will significantly affect
performance. Only change a setting after reading
and understanding this entire manual.
warning
The Enter key must be pressed to save any changes
made to a setting.
®

Model MSX Make-Up Air 25

Troubleshooting
Blower Does Not Operate

Proper supply power at
main disconnect

Check main voltage
(See Blower Start-Up Step #1)
Main Disconnect (DS1) Off
(Turn Main Disconnect DS1 On)
Primary fuses blown
(Replace fuses)

Yes

24 VAC between
terminals R and X?

Main Transformer (TR1) Defective
(Replace transformer)

Yes

24 VAC between
terminals G and X?

Yes

24 VAC across
terminals 3 and X?

Yes

24 VAC across
terminals 4 and X?

Yes

Supply Fan Overload (ST1 OL) tripped
(Reset and check motor amps. Reference Blower Start-Up #4)
Optional Exhaust Fan Interlocks (ST2-ST5) open
(Correct/Replace)

(Optional) Freeze Protection (RT4) Tripped
(Reset)

Yes

24 VAC across A2 and A1 on
supply contactor (ST1)

Supply Switch (S2) Off
(Turn Supply Switch (S2) On)
Fire System Contact (FSC) tripped/not installed
(Correct/Replace)

(Optional) Damper Limit Switch (DL1) holding
(Wait for actuator to open fully or adjust limit switch)
(Optional) Damper Limit Switch jumper missing
(Install jumper. Reference the unit’s ladder diagram for terminals)
Fan Relay (RF) is not energized
(Check for loose connection) (Repair or replace relay)
Broken fan Bbelt
(Replace. Reference Maintenance section)
Defective motor or capacitor
(Repair/Replace)
Blown motor fuse
(Replace)
One or more legs of 3 phase is out
(Restore missing legs)

At this time the supply contactor (ST1) should pull in,
passing power to the supply motor
and the blower should start.

26 Model MSX Make-Up Air

Troubleshooting
Motor Overamps

Air volume too high?

Yes

Adjust drives or increase external
static pressure as needed.

(Reference Blower Start-Up Step #5)

Actual static pressure
lower than design?

Yes

Adjust drives to reduce blower RPM.

(Reference Blower Start-Up Step #5)

Blower rotation correct?

Reverse blower rotation.

Yes

(Reference Blower Start-Up Step #2)

Motor voltage correct?

Provide proper power supply.

Yes

(Reference Blower Start-Up Step #1)

Motor horsepower too low?

Yes

Shorted windings in motor?
Yes

Resize motor.
Yes

Replace motor.

Everything is working
properly, consult factory.

Model MSX Make-Up Air 27

Troubleshooting
Insufficient Airflow
Damper(s) not fully opened?

Yes

Adjust damper linkage(s), or replace faulty actuator(s).

(Damper actuators may take a few minutes to open)

System static losses too high?

Yes

Blower speed too low?

Reduce losses by improving ductwork.
Yes

Adjust drives as needed.

(Reference Blower Start-Up Step #5)

Filters dirty or clogged

Yes

Clean or replace filters.

(Reference Filter Maintenance in the Maintenance section).

Leaks in ductwork

Yes

Belt slipping

Repair leaks.
Yes

Replace or tighten belt.

Yes

(Reference V-Belt Maintenance in the Maintenance section)

Everything is working properly,
consult factory.

Too Much Airflow
Blower speed too high?

Yes

Adjust drives as needed.

(Reference Blower Start-Up Step #5)

Filters not in place?

Yes

Insufficient external static
pressure?

Install filters.
Yes

Everything is working properly,
consult factory.
28 Model MSX Make-Up Air

Increase external static pressure.

Troubleshooting
Excessive Noise or Vibration

Belts worn or loose?

Yes

Replace worn belts or tighten loose belts.
(Reference V-Belt Drive Maintenance in the Maintenance section)

Sheaves aligned?

Align sheaves.
(Reference V-Belt Drive Maintenance in the Maintenance section)

Yes

Wheel unbalanced?

Yes

Clean and/or balance wheel(s).
No

Bearings worn or need
lubrication?

Yes

Replace worn bearings or lubricate bearings as needed.
(Reference Bearing Maintenance in the Maintenance section)

Wheel rubbing on inlet?

Yes

Adjust wheel(s) or inlet.
No

At this time noise and vibration should
be at acceptable levels.

Model MSX Make-Up Air 29

Troubleshooting
Electric Heater Does Not Operate (optional)
Supply fan must be on for heater to operate

24 VAC between
terminals W1 and X?

Yes

24 VAC between
terminals 22 and 21?

Main Transformer (TR2) defective
(Replace transformer)

Yes

24 VAC between
terminal A2 on heat relay (RH)
and X?

(Optional) Inlet Air Sensor (TS4) holding
(Adjust (TS4) setting. Reference Blower Start-Up Step #6)

Yes

24 VAC between
terminals T1 and 21?

Heat Relay (RH) is not energized
(Check for loose connections). (Repair or replace Heat Relay (RH))

Yes

24 VAC between
terminals I and 21?
Yes

Heat Switch (S4) Off
(Turn Heat Switch (S4) On)
Heat Switch not wired
(Wire Heat Switch (S4))

Pressure Differential Switch (PDS) open
(Check on cause of control loss)
Automatic and/or Manual Reset Cutouts (A and M) tripped
(Reset/Replace Automatic and/or Manual Reset Cutouts (A and M))
(Check on cause of control loss)
At this time the heater should be energized.
(The heating elements will not be on if the leaving air
temperature is above its set point on the Remote Adjuster (RA))

30 Model MSX Make-Up Air

Troubleshooting
Evaporative Cooler does not Operate (Recirculating pump)
Supply fan must be on for cooler to operate

24 VAC between terminals
Y1 and X

Cool Switch (S4) off
(Turn Cool Switch (S4) on)
Cool Switch not wired
(Wire Cool Switch (S4))

Yes

24 VAC between terminal A2 on
Cooling Relay (RC) and X

Optional Inlet Air Sensor (TS4) holding
(Adjust TS4 setting. Reference Blower Start-Up Step #6)

Yes

115 VAC between terminals
102 and 101

Cooling Transformer (TR4) defective
(Replace transformer)

Yes

115 VAC between terminal
114 and 101

Cooling Relay (RC) is not energized
(Check for loose connections)
(Repair or replace relay)

Yes

At this time the evaporative cooler pumps should be on

Water Blows through Evaporative Cooler
Are the headers in place and
located near the entering
air side of the media?

Replace headers and/or move the headers.
(Reference Evaporative Cooler Start-Up Step #1)

Yes

Water supply greater than
evaporation and bleed-off rate?

Yes

Use the main supply valve to reduce the supply of water.
No

Air velocity greater than
specified?

Yes

Reduce the air velocity through the media.
(Reference Blower Start-Up Step #5)

At this time the evaporative cooler should be
operating without water blowing through.

Model MSX Make-Up Air 31

Troubleshooting
Water Wizard™ — Improper Water Supply
note

note

If the water supply is too low, the media will
continuously appear dry.
note

Changing the On Time Factor by (1) will change the
water supply by approximately 3%.
important

If the water supply is too high, the media will be
saturated and excessive water will be draining from
the sump tank.
note
Some water drainage is desired to keep the media
flushed, but it should be minimized to utilize the
Water Wizard™.

The enter key must be pressed to save the new On
Time Factor.

4. Exit Program Mode

After 15 seconds of idle time the controller will
automatically exit Program Mode

1. Adjust the Manual Supply Valve

Adjust the manual supply valve (refer to Start-Up,
Water Wizard™). If the recommended water pressure
does not provide enough water, increase the pressure
until the desired water supply is achieved. If the
recommended water pressure provides too much
water, decrease the water pressure until the desired
water supply is achieved.
caution
Only proceed to Steps 2 and 3 if Step 1 does not
correct the problem.

2. Enter Program Mode
Press and hold
the Enter key for
three seconds to enter
Program Mode. The
display will read “Pro”
when Program Mode is
active.

Program Display

3. Adjust the On Time Factor

While in the Program Menu, use the Up and
Down keys to navigate through the menu
options until “ont” is displayed.
With “ont” displayed, press the Enter key to
access the setting.

With the setting displayed, use the Up and Down keys
to adjust the setting as needed.
Increase the factor to increase the water supply or
decrease the factor to decrease the water supply.
Press the Enter key to
save the new On Time
Factor and return to the
Program Menu.

On Time Factor Display

32 Model MSX Make-Up Air

Maintenance - Routine
Snow Accumulation

Caution
Lock-out the gas and the electrical power to the
unit before performing any maintenance or service
operations to this unit.

V-Belt Drives

V-belt drives must be checked on a regular basis for
wear, tension, alignment, and dirt accumulation.
Check the tension by measuring the deflection in the
belt as shown below.
Check the alignment by using a straight edge across
both sheaves as shown below.

Clear snow away from roof mounted units. Keep the
snow clear of the intake and access doors.

Motors
Motor maintenance is generally limited to cleaning
and lubrication (where applicable).
Cleaning should be limited to exterior surfaces only.
Removing dust and grease build-up on the motor
assures proper motor cooling.
Motors supplied with grease fittings should be
greased in accordance with the manufacturer’s
recommendations.
important

important
Premature or frequent belt failures can be caused by
improper belt tension, or misaligned sheaves.
•

Abnormally high belt tension or drive
misalignment will cause excessive bearing loads
and may result in failure of the fan and/or motor
bearings.
• Abnormally low belt tension will cause squealing
on start-up, excessive belt flutter, slippage, and
overheated sheaves.

important
Do not pry belts on or off the sheave. Loosen belt
tension until belts can be removed by simply lifting
the belts off the sheaves.
important

Do not allow water or solvents to enter the motor
or bearings. Motors and bearings should never be
sprayed with steam, water or solvents.
important
Greasing motors is only intended when fittings are
provided. Many motors are permanently lubricated,
requiring no additional lubrication.

Wheels
Wheels require little attention when moving clean air.
Occasionally oil and dust may accumulate on the wheel
causing imbalance. When this occurs the wheel and
housing should be cleaned to assure proper operation.

When replacing V-belts on multiple groove drives,
all belts should be changed to provide uniform drive
loading.
important
Do not install new belts on worn sheaves. If the
sheaves have grooves worn in them, they must be
replaced before new belts are installed.
FAN

MOTOR

MOTOR
FAN

Deflection = Belt Span
64

Belt Span

Belt Tension

Drive Alignment

Model MSX Make-Up Air 33

Maintenance - Routine

continued

Bearings

Filters

The bearings for Greenheck fans are carefully selected
to match the maximum load and operating conditions
of the specific class, arrangement and fan size.
The instructions provided in this manual and those
provided by the bearing manufacturer will minimize
any bearing problems.

Filter maintenance is generally limited to cleaning and
replacement.

IMPORTANT

If disposable filters are installed, they can be checked
by holding up to a light source. If light cannot pass
through the filter, it should be replaced.

Lubricate bearings prior to periods of extended
shutdowns or storage and rotate shaft monthly to
aid in corrosion prevention. If the fan is stored more
than three months, purge the bearings with new
grease prior to start-up.
Recommended Bearing Lubrication Schedule (in Months*)
Fan
RPM

Bearing Bore Size (inches)
⁄2 - 1

11⁄8 - 11⁄2

15⁄8 - 17⁄8

115⁄16 - 23⁄16

27⁄16 - 3

250

500

750

1000

1250

1500

0.5

2000

0.5

0.25

*Suggested initial greasing interval is based on 12 hour
per day operation and 150°F (66°C) maximum housing
temperature. For continuous (24 hour) operation, decrease
greasing interval by 50%
• If extended grease lines are present, relubricate while in
operation, only without endangering personnel.
• For ball bearings (operating) relubricate until clean grease
is seen purging at the seals. Be sure not to unseat the seal
by over lubricating.
• For ball bearings (idle) add 1-2 shots of grease up to 2
inch bore size, and 4-5 shots above 2 inch bore sizes with
a hand grease gun.
• For roller bearings add 4 shots of grease up to 2 inch bore
size, and 8 shots for 2-5 inch bore size with a hand grease
gun.
• Adjust relubrication frequency based on condition of
purged grease.
• A high quality lithium based grease conforming to NLGI
Grade 2 consistency, such as those listed here:
Mobil 532
Mobilux #2

Texaco Multifak #2
Texaco Premium #2

If aluminum mesh filters are installed, they can be
washed in warm soapy water.
An adhesive spray can be added to aluminum mesh
filters to increase their efficiency.

IMPORTANT
When reinstalling filters, be sure to install them
with the airflow in the correct direction. An airflow
direction arrow is located on the side of the filters.
IMPORTANT
Replacement filters should be from the same
manufacturer and the same size as the original
filters provided with the unit.

Evaporative Coolers

The media should be periodically brushed lightly with
a soft bristle brush in an up and down motion while
flushing with water. This aids in reducing the amount
of mineral build-up.
For large amounts of mineral build-up, clean or
replace the media and increase the water bleed-off or
flush rate.
The cooling media has a useful life of 3 to 5 years
depending on the water quality and the bleed-off or
flush rate.
important
When reinstalling the evaporative media, make sure
that it is installed correctly. Reference the drawing
shown below.
important
Replacement media should be from the same
manufacturer and be the same size as the original
media provided with the unit.

45º

B Shell Alavania #2
Exxon Unirex #2
Entering Air

Leaving Air

15º

Media Orientation

34 Model MSX Make-Up Air

Maintenance - Routine

continued

Cooling Coils
warning
Repair and replacement of the coil and the
connecting piping, valves, etc., should be performed
by a qualified individual.
Inspect the coil for signs of corrosion and/or leaks.
Repair any leaks as required.
Inspect the coil’s surface for foreign material. If the
coil surface needs cleaning, clean the coil from the
leaving air-side so that foreign material will be washed
out of the coil rather than pushed farther in.
Inspect and clean the drain pan to prevent the growth
of algae and other organisms.
important
Be sure to read and follow the manufacturer’s
recommendations before using any cleaning fluid.
caution
Caution should be used to avoid injury when venting
the coil. High pressure and/or high temperature
fluids can cause serious injuries.

Chilled Water Coils

Test the circulating fluid for sediment, corrosive
products and biological contaminants. Make the
necessary corrective measures.
Maintain adequate fluid velocities and proper filtering
of the fluid.
If automatic air vents are not utilized, periodic venting
of the coil is recommended to remove accumulated air.

Model MSX Make-Up Air 35

Maintenance - Fall
Evaporative Coolers

The water should be shut off and all the lines drained
when the outside temperature drops below 45°F.
Remove drain plugs for the winter.
Clean all interior parts of any mineral deposits or foreign
materials that may have built-up during the cooling
season.
Replace any worn or non-functioning parts.

Winterizing Chilled Water Coils

During the winter, chilled water coils need to be
protected against freezing. Greenheck recommends
protecting the coils by either blowing-out the coils or
by flushing the coils.

Blowing-Out Coils

1. Close valves on the supply and return lines.
2. Open drain valves and/or drain plug. Remove
vent plug to allow coil to drain faster.
3. After coil is fully drained, connect a blower to the
caps. Do not connect the blower to the air vent
or drain plug.
4. Close the vent plug on the header that the blower
is connected to. Open the drain valve or cap on
the other header.
5. Turn on blower for 30 minutes. Place mirror at
discharge. If the mirror fogs up, repeat procedure
until no fog appears on the mirror.
6. After drying the coil, wait a few minutes then
repeat Step #5.
7. Leave drains open and do not install plugs until
beginning of cooling season.

Flushing Coils

Greenheck recommends the use of inhibited glycol
(such as propylene or ethylene) to flush water coils
to protect against freezing. Additionally, the use of
inhibited glycol provides corrosion protection.
The table below indicate the percentage of glycol
required to prevent freezing in a coil at a given outdoor
air freeze point. Completely fill coil with solution. Drain
coil. Residual glycol fluid per these concentrations
can be left in the coil without concern of freezing.
Recovered fluid can be used to flush other coils.
Percent of
Ethylene
Glycol
by Volume

Freeze Point
°F

ºC

Percent of
Propylene
Glycol
by Volume

Freeze Point
°F

ºC

-4

-3

-9

-7

-16

-13

-25

-7

-22

-34

-37

-28

-33

-55

-48

-60

-51

36 Model MSX Make-Up Air

Reference
Typical Control Center Layout
MSX

Unit Control Center Layout

1
2

4
9 11

15
12
13

1. Primary Fuses — provides proper fusing to low
voltage transformer.
2. Low Voltage Transformer — provides low
voltage to controls and optional evaporative
cooling controls.
3. Low Voltage Fuse — provides proper fusing
to controls and optional evaporative cooling
controls.
4. Control Terminal Block — provides wiring
access to controls.
5. Building Freeze Protection Timer (optional) —
prevents the discharge of cold air into the
building.
6. Fan Relay — allows power to pass to energize
motor starter.
7. Supply Motor Starter — 24 volt magnetic
contacts for starting supply motor.
8. Supply Overload — provides electronic
overload protection to supply motor.
9. Auxiliary Contact (optional) — provides one
normally closed and one normally open contact
for other equipment.

17
16
14
6

10. Exhaust Fuses (optional) — provides proper
fusing for exhaust fan motor(s).
11. Exhaust Motor Starter (optional) — 24 volt
magnetic contacts for starting exhaust motor.
12. Exhaust Overload (optional) — provides
electronic overload protection to exhaust motor.
13. Inlet Air Sensor (optional) — outdoor air stat
that automatically controls the cooling based on
outdoor air temperature.
14. Cooling Relay (optional) — allows power to
pass to cooling controls.
15. Reset Timer (optional) — resets cooling system
to run a time interval.
16. Auto Drain Relay (optional) — assures supply
pump does not operate during drain interval.
Allows pump to operate in cooling mode.
17. Cooling Timer (optional) — allows for
automatic draining of the evaporative cooling
system based on time schedule.
18. Dirty Filter Switch (optional) — monitors filter
pressure drop, turns on indicating light when
pressure drop is above field adjustable set point.

Dirty Filter Switch
Common
Normally Open
Normally Closed
CCW to Decrease Trip Point
CW to Increase Trip Point
Negative Pressure
after the filters
Positive Pressure
before the filters

Model MSX Make-Up Air 37

Start-Up Checklist
Start-Up Checklist
Unit Model Number ________________________________
(e.g. MSX-120-H32-DB)

Unit Serial Number ________________________________
(e.g. 10111000)

Start-Up Date
________________________________
Start-Up Personnel Name___________________________
Start-Up Company ________________________________
Phone Number

________________________________

Pre Start-Up Checklist – check boxes as items
are completed.
o Check tightness of all factory wiring connections
o Verify control wiring wire gauge
o Hand-rotate blower to verify free rotation
o Verify supply voltage to the main disconnect
o Verify the supply gas pressure
o Verify remote controls wiring

Start-Up Electric Heater (optional) – refer to
Electric Heater Start-Up section for further detail.
o Check line voltage
L1-L2___________

L2-L3 ___________

L1-L3___________
o Set the unit’s operating temperature

_________ °F
Start-Up Evaporative Cooler (optional) – refer
to Evaporative Cooler Start-Up section for further
detail.
o Check media orientation

o Check for proper water flow to distribution
headers

o Check for distribution header orientation to

prevent water spillage

Start-Up Blower Checklist – refer to Blower

Start-Up section for further detail.
L1-L2___________

L2-L3 ___________

L1-L3___________
o Check blower rotation
o Check for vibration
o Supply fan RPM
__________ RPM
o Motor nameplate amps __________ Amps
o Actual motor amps
__________ Amps
o Actual CFM delivered
__________ CFM

o Check line voltage

Optional Accessories – refer to Blower Start-Up
section, Step #6 for further detail.
o Heating Inlet Air Sensor

_________ Actual Setting
Typical setting 60º-70ºF (15º-21ºC)

o Cooling Inlet Air Sensor

_________ Actual Setting
Typical setting 75ºF (24ºC

o Building Freeze Protection

_________ Actual Setting
Typical setting 5 minutes; 45ºF (7ºC)

o Dirty Filter Gauge

_________ Actual Setting
Typical setting varies

38 Model MSX Make-Up Air

Maintenance Log
Date___________________ Time______________ AM/PM