CARRIER Package Units(both Units Combined) Manual L1001389
User Manual: CARRIER CARRIER Package Units(both units combined) Manual CARRIER Package Units(both units combined) Owner's Manual, CARRIER Package Units(both units combined) installation guides
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Page Count: 40
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®
Turn to the Expertg
Installation Instructions
NOTE: Read the entire instruction manual before starting the
installation.
NOTE: Installer: Make sure the Owner's Manual and Service
Instructions are left with the unit after installation,
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS ......................... 1
INTRODUCTION ................................... 2
RECEIVING AND INSTALLATION ................. 2-14
Check Equipment .................................. 2
Identify Unit .................................... 2
Inspect Shipment ................................. 2
Provide Unit Support ............................... 2
Roof Curb ...................................... 2
Slab Mount ..................................... 2
Field Fabricate Ductwork ............................ 2
Provide Clearances ................................. 3
Rig and Place Unit ................................. 7
Connect Condensate Drain ........................... 8
Install Flue Hood ................................... 8
Install Gas Piping .................................. 8
Install Duct Connections ............................. 9
Configuring Units for Downflow (Vertical)
Discharge ...................................... 9
Install Electrical Connections ........................ 13
High-Voltage Connections ........................ 13
Special Procedures for 208-V Operation .............. 13
Control Voltage Connections ....................... 13
Balance Point Setting Thermidistat or Hybrid Heat
Thermostat .................................... 14
Transformer Protection ........................... 14
PRE-START-UP ................................... 14
START-UP ..................................... 15-19
Check for Refrigerant Leaks ......................... 15
Unit Sequence of Operation ......................... 15
Start-Up Heating and Make Adjustments ............... 15
Checking Heating Control ......................... 16
Check Gas Input ................................ 16
Adjust Gas Input ................................ 16
Check Burner Flame ............................. 17
Start-Up Cooling and Make Adjustments ............... 18
Checking Cooling Control Operation ................ 18
Checking and Adjusting Refrigerant ................. 18
Indoor Airflow and Airflow Adjustments ............. 18
Continuous Fan Operation ........................ 19
MAINTENANCE ................................ 29-35
Air Filter ........................................ 29
Indoor Blower and Motor ........................... 29
Flue Gas Passageways .............................. 30
Limit Switch ..................................... 30
Burner Ignition ................................... 30
Main Burners .................................... 30
Outdoor Coil, Indoor Coil, & Condensate Drain Pan ...... 30
A0g033
Fig. 1 - Unit 48VT-A
Outdoor Fan ..................................... 31
Electrical Controls and Wiring ....................... 31
Refrigerant Circuit ................................. 31
Gas Input ........................................ 32
Indoor Airflow ................................... 32
Check Defrost Thermostat ........................... 32
Puron® Items .................................... 32
TROUBLESHOOTING .............................. 35
START-UP CHECKLIST ............................ 35
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause death, personal injury, or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified
installer or agency must use factory-authorized kits or accessories
when modifying this product. Refer to the individual instructions
packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Have a fire extinguisher available. Read these
instructions thoroughly and follow all warnings or cautions
included in literature and attached to the unit. consult local
building codes, the current editions of the National Fuel Gas Code
(NFGC) NFPA 54/ANSI Z223.1, and the National Electrical Code
(NEC) NFPA 70.
In Canada refer to the current editions of the National Standards of
Canada CAN/CSA-BI49.1 and .2 Natural Gas and Propane
Installation codes, and Canadian Electrical Code CSA C22A
Recognize safety information. This is the safety-alert symbol /_.
When you see this symbol on the unit and in instructions or manu-
als, be alert to the potential for personal injury. Understand these
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signalwords:DANGER,WARNING,andCAUTION.These
wordsareusedwiththesafety-alertsymbol.DANGERidentifies
themostserioushazardswhichwill result in severe personal iniury
or death. WARNING signifies hazards which could result in per-
sonal injury or death. CAUTION is used to identify unsafe practic-
es which may result in minor personal injury or product and prop-
erty damage. NOTE is used to highlight suggestions which will
result in enhanced installation, reliability, or operation.
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal
iniury or death.
Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch. Turn off accessory heater power switch if
applicable. TAG THE DISCONNECT SWITCH WITH A
SUITABLE WARNING LABEL.
FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
iniury, death or property damage.
A qualified installer or agency must use only
factory-authorized kits or accessories when modifying this
product.
CUT HAZARD
Failure to follow this caution may result in personal iniury.
When removing access panels (see Fig. 19) or performing
maintenance functions inside your unit, be aware of sharp
sheet metal parts and screws. Although special care is taken
to reduce sharp edges to a minimum, be extremely careful
when handling parts or reaching into the unit.
INTRODUCTION
The 48VT-A unit (see Fig. 1) is a fully self-contained,
combination Category I gas heating/electric heating and cooling
unit designed for outdoor installation (See Fig. 2 and 3 for unit
dimensions). All unit sizes have return and discharge openings for
both horizontal and downflow configurations, and are factory
shipped with all downflow duct openings covered. Units may be
installed either on a rooftop, a cement slab, or directly on the
ground, if local codes permit (See Fig. 4 for roof curb dimensions).
Models with an N in the fifth position of the model number are
dedicated Low NOx units designed for California installations.
These models meet the California maximum oxides of nitrogen
(NOx) emissions requirements of 40 nanograms/joule or less as
shipped from the factory and must be installed in California Air
Quality Management Districts or any other regions in North
America where a Low NOx rule exists.
RECEIVING AND INSTALLATION
Step 1-- Check Equipment
IDENTIFY UNIT
The unit model number and serial number are stamped on the unit
information plate. Check this information against shipping papers.
INSPECT SHIPMENT
Inspect for shipping damage before removing packaging materials.
If unit appears to be damaged or is torn loose from its anchorage,
have it examined by transportation inspectors before removal.
Forward claim papers directly to transportation company.
Manufacturer is not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify the
nearest equipment distribution office if any item is missing. To
prevent loss or damage, leave all parts in original packages until
installation.
If the unit is to be mounted on a curb in a downflow application,
review Step 9 to determine which method is to be used to remove
the downflow panels before rigging and lifting into place. The
panel removal process may require the unit to be on the ground.
Step 2 -- Provide Unit Support
For hurricane tie downs, contact distributor for details and PE
(Professional Engineering) Certificate if required.
ROOF CURB
Install accessory roof curb in accordance with instructions shipped
with curb (See Fig. 4). Install insulation, cant strips, roofing, and
flashing. Ductwork must be attached to curb.
IMPORTANT: The gasketing of the unit to the roof curb is
critical for a water tight seal. Install gasketing material supplied
with the roof curb. Improperly applied gasketing also can result in
air leaks and poor unit performance.
Curb should be level to within 1/4 in. (6 mm). This is necessary for
unit drain to function properly. Refer to accessory roof curb
installation instructions for additional information as required.
Installation on older "G" series roof curbs.
Two accessory kits are available to aid in installing anew "G"
series unit on an old "G" roof curb.
1. Accessory kit number CPADCURB001A00, (small chassis)
and accessory kit number CPADCURB002A00, (large
chassis) includes roof curb adapter and gaskets for the
perimeter seal and duct openings. No additional
modifications to the curb are required when using this kit.
2. An alternative to the adapter curb is to modify the existing
curb by removing the outer horizontal flange and use
accessory kit number CPGSKTKIT001A00 which includes
spacer blocks (for easy alignment to existing curb) and
gaskets for the perimeter seal and duct openings. This kit is
used when existing curb is modified by removing outer
horizontal flange.
UNIT/STRUCTURAL DAMAGE HAZARD
Failure to follow this caution may result in property damage.
Ensure there is sufficient clearance for saw blade when cutting
the outer horizontal flange of the roof curb so there is no
damage to the roof or flashing.
SLAB MOUNT
Place the unit on a solid, level concrete pad that is a minimum of 4
in. (102 mm) thick with 2 in. (51 mm) above grade. The slab
should be flush on the compressor end of the unit (to allow
condensate drain installation) and should extend 2 in. (51 mm) on
the three remaining sides of the unit. Do not secure the unit to the
slab except when required by local codes.
Step 3-- Field Fabricate Ductwork
Secure all ducts to roof curb and building structure on vertical
discharge units. Do not connect ductwork to unit. For horizontal
applications, unit is provided with flanges on the horizontal
openings. All ductwork should be secured to the flanges. Insulate
and weatherproof all external ductwork, joints, and roof openings
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withcounterflashingandmasticinaccordancewithapplicable
codes.
Ductspassingthroughanunconditionedspacemustbeinsulated
andcoveredwithavaporbarrier.
If aplenumreturnisusedonaverticalunit,thereturnshouldbe
ductedthroughtheroofdecktocomplywithapplicablefirecodes.
Readunitratingplateforanyrequiredclearancesaroundductwork.
Cabinetreturn-airstaticshallnotexceed-.25IN.W.C.
Step 4-- Provide Clearances
The required minimum operating and service clearances are shown
in Fig. 2 and 3.
IMPORTANT: Do not restrict outdoor airflow. An air restriction
at either the outdoor-air inlet or the fan discharge may be
detrimental to compressor life.
The condenser fan pulls air through the condenser coil and
discharges it through the top grille. Be sure that the fan discharge
does not recirculate to the condenser coil. Do not locate the unit in
either a corner or under an overhead obstruction. The minimum
clearance under a partial overhang (such as a normal house
overhang) is 48-in. (1219 mm) above the unit top. The maximum
horizontal extension of a partial overhang must not exceed 48-in.
(1219 mm).
Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. Do not install the unit on
carpeting or other combustible materials. The unit may be installed
on wood flooring or on Class A, B, or C roof covering materials.
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Fig. 3 - 48VT-A36-60 []nit Dimensions
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HVACunitI
baserails
Anchor screw j
Flashing field
supplied _
Gasket
j Roofcurb
Wood nailer*
/Roofcurb*
Insulation
/(field supplied)
Roofing material
field supplied
Cant strip _/ t
/
A09090
ROOF CURB DETAIL
SMALL CURB A09418
F A
E
LARGE CURB A09415
A09419
B C D F
IN. (mm)* IN. (mm) IN. (mm) IN. (mm)
UNIT SIZE
Small
Large
NOTES:
CATALOG
NUMBER
CPRFCURB010A00
CPRFCURB011A00
CPRFCURB012A00
CPRFCURB013A00
A
IN. (mm)
11 (279)
14 (356)
11 (279)
14 (356)
10 (254)
14 (356)
16 (406) 47.8
(1214)
1. Roof curb must be set up for unit being installed.
2. Seal strip must be applied, as required, to unit being installed.
3. Roof curb is made of 16-gauge steel.
4. Attach ductwork to curb (flanges of duct rest on curb).
5. Insulated panels: 1-in. (25.4 mm) thick fiberglass 1 lb. density.
IMPORTANT: Do not install large base pan HYBRID HEAT
units onto the small base pan (common curb). The center of gravity
on a large base pan HYBRID HEAT unit could overhang the curb
causing an unsafe condition. Before installing any large base pan
unit onto the common curb, check the "Y" distance in the product
Fig. 4 - Roof Curb Dimensions
E
IN. (mm)
32.4 (822)
43.9
(1116)
2.7 (69)
G H
IN. (mm) IN. (mm)
30.6 (778)
46.1 (1170)
42.2 (1072)
literature dimensional drawing to ensure that "Y" is greater than 14
in. (356 ram). Do not install any large base pan unit onto the
common curb with a "Y" dimension (center of gravity) less than 14
in. (356 mm).
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JMINIMUM HEIGHT: 36" (9!4.4 ram)
HAUTEUR MINIMUM
DUCTS
SEE DE,TAIL A
VOIB DETAIL A
UNIT HEIGHT
HAUTEUR D'UNITEJ"
DETAIL A
VOIR DIETAIL A
SEAL STRIP MUST BE IN BANDE SCELLANT BOIT ETRE
PLACE BEFORE PLACING EN PL,_C E AVANT DE PLACER
UNIT ON ROOF CURB L=U NITE SUR LA BASE DE TOIT
50CY502286 2,0
A09051
24 30 36
Unit Unit
Ib kg Ib kg Ib kg Ib
Rigging 374 170 366 166 Rigging 448 203 494
Weight Weight
42 48 60
kg Ib kg Ib kg
224 514 233 548 249
NOTE: See dimensional drawing for corner weight distribution.
Fig. 5 -48VT-A Suggested Rigging
Step 5 -- Rig and Place Unit Inspection
PERSONAL INJURY OR PROPERTY DAMAGE
HAZARD
Failure to follow this warning could result in personal
iniury, death or property damage.
When installing the unit on a rooftop, be sure the roof will
support the additional weight.
Rigging and handling of this equipment can be hazardous for
many reasons due to the installation location (roofs, elevated
structures, etc.).
Only trained, qualified crane operators and ground support staff
should handle and install this equipment.
When working with this equipment, observe precautions in the
literature, on tags, stickers, and labels attached to the equipment,
and any other safety precautions that might apply.
Training for operators of the lifting equipment should include, but
not be limited to, the following:
1. Application of the lifter to the load, and adjustment of the
lifts to adapt to various sizes or kinds of loads.
2. Instruction in any special operation or precaution.
3. Condition of the load as it relates to operation of the lifting
kit, such as balance, temperature, etc.
Follow all applicable safety codes. Wear safety shoes and work
gloves.
Prior to initial use, and at monthly intervals, all rigging shackles,
clevis pins, and straps should be visually inspected for any
damage, evidence of wear, structural deformation, or cracks.
Particular attention should be paid to excessive wear at hoist
hooking points and load support areas. Materials showing any kind
of wear in these areas must not be used and should be discarded.
UNIT FALLING HAZARD
Failure to follow this warning could result in personal
iniury or death.
Never stand beneath rigged units or lift over people.
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal
iniury/death or property damage.
When straps are taut, the clevis should be a minimum of 36
in. (914 mm) above the unit top cover.
Ri_gin_/Liftin_ of Unit (See Fi_. 5)
Lifting holes are provided in base rails as shown in Fig. 2 and 3.
1. Leave top shipping skid on the unit for use as a spreader bar
to prevent the rigging straps from damaging the unit. If the
skid is not available, use a spreader bar of sufficient length
to protect the unit from damage.
2. Attach shackles, clevis pins, and straps to the base rails of
the unit. Be sure materials are rated to hold the weight of the
unit (See Fig. 5).
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3. Attach a clevis of sufficient strength in the middle of the
straps. Adjust the clevis location to ensure unit is lifted level
with the ground.
After the unit is placed on the roof curb or mounting pad, remove
the top skid.
Step 6-- Connect Condensate Drain
NOTE: When installing condensate drain connection be sure to
comply with local codes and restrictions.
Model 48VT-A disposes of condensate water through a 3/4 in.
NPT fitting which exits through the compressor access panel (See
Fig. 2 and 3for location).
Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in ground
level installations. Install a field-supplied condensate trap at end
of condensate connection to ensure proper drainage. Make sure that
the outlet of the trap is at least 1 in. (25 mm) lower than the
drain-pan condensate connection to prevent the pan from
overflowing (See Fig. 6). Prime the trap with water. When using a
gravel apron, make sure it slopes away from the unit.
If the installation requires draining the condensate water away
from the unit, install a 2-in. (51 mm) trap at the condensate
connection to ensure proper drainage (See Fig. 6). Make sure that
the outlet of the trap is at least 1 in. (25 mm) lower than the
drain-pan condensate connection. This prevents the pan from
overflowing.
Prime the trap with water. Connect a drain tube - using a minimum
of 3/4-in. PVC or 3/4-in. copper pipe (all field-supplied) - at the
outlet end of the 2-in. (51 mm) trap. Do not undersize the tube.
Pitch the drain tube downward at a slope of at least 1-in. (25 mm)
for every 10 fl (3 m) of horizontal run. Be sure to check the drain
tube for leaks.
l-in. (25 ram) rain.
TRAP
@1 mm) min.
A09052
Fig. 6 - Condensate Trap
Step 7 -- Install Flue Hood
The flue assembly is secured and shipped in the return air duct.
Remove duct cover to locate the assembly (See Fig. 8).
NOTE: Dedicated low NOx models MUST be installed in
California Air Quality Management Districts where a Low NOx
rule exists.
These models meet the California maximum oxides of nitrogen
(NOx) emissions requirements of 40 nanograms/joule or less as
shipped from the factory.
NOTE: Low NOx requirements apply only to natural gas
installations.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
iniury or death.
The venting system is designed to ensure proper venting.
The flue hood assembly must be installed as indicted in this
section of the unit installation instructions.
Install the flue hood as follows:
1. This installation must conform with local building codes
and with the National Fuel Gas Code (NFGC) NFPA 54 /
ANSI Z223A, (in Canada, CAN/CGA BI49A, and
B149.2) latest revision. Refer to Provincial and local
plumbing or wastewater codes and other applicable local
codes.
2. Remove flue hood from shipping location (inside the return
section of the blower compartment-see Fig. 8). Remove the
return duct cover to locate the flue hood. Place flue hood
assembly over flue panel. Orient screw holes in flue hood
with holes in the flue panel.
3. Secure flue hood to flue panel by inserting a single screw on
the top flange and the bottom flange of the hood.
Step 8-- Install Gas Piping
The gas supply pipe enters the unit through the access hole
provided. The gas connection to the unit is made to the l/2-in.
(12.7 mm) FPT gas inlet on the gas valve.
Install a gas supply line that runs to the heating section. Refer to
Table 2 and the NFGC for gas pipe sizing. Do not use cast-iron
pipe. It is recommended that a black iron pipe is used. Check the
local utility for recommendations concerning existing lines. Size
gas supply piping for 0.5 IN. W.C. maximum pressure drop. Never
use pipe smaller than the l/2-in. (12.7 mm) FPT gas inlet on the
unit gas valve.
For natural gas applications, the gas pressure at unit gas connection
must not be less than 4.0 IN. W.C. or greater than 13 IN. W.C.
while the unit is operating. For propane applications, the gas
pressure must not be less than 11.0 IN. W.C. or greater than 13 IN.
W.C. at the unit connection.
A l/8-in. (3.2 mm) NPT plugged tapping, accessible for test gauge
connection, must be installed immediately upstream of the gas
supply connection to the gas valve.
When installing the gas supply line, observe local codes pertaining
to gas pipe installations. Refer to the NFGC NFPA 54/ANSI
Z223.1 latest edition (in Canada, CAN/CGA B149.1).
NOTE: In the state of Massachusetts:
1. Gas supply connections MUST be performed by a licensed
plumber or gas fitter.
2. When flexible connectors are used, the maximum length
shall not exceed 36 in. (915 mm).
3. When lever handle type manual equipment shutoff valves
are used, they shall be T-handle valves.
4. The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.
In the absence of local building codes, adhere to the following
pertinent recommendations:
1. Avoid low spots in long runs of pipe. Grade all pipe 1/4 in.
(6.35 mm) for every 15 ft (4.6 m) of length to prevent traps.
Grade all horizontal runs downward to risers. Use risers to
connect to heating section and to meter.
2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate straps,
hangers, etc. Use a minimum of one hanger every 6 ft (1.8
m). For pipe sizes larger than 1/2 in., (12.7 mm) follow
recommendations of national codes.
3. Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.
4. Install sediment trap in riser leading to heating section (See
Fig. 7). This drip leg functions as a trap for dirt and
condensate,
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IN
I
TEE
NIPPLE
CAP
C99020
Fig. 7 - Sediment Trap
5. Install an accessible, external, manual main shutoff valve in
gas supply pipe within 6 fl (1.8 m) of heating section.
6. Install ground-joint union dose to heating section between
unit manual shutoff and external manual main shut-off
valve.
7. Pressure test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig. Pressure test the
gas supply piping system at pressures equal to or less than 0.5 psig.
The unit heating section must be isolated from the gas piping
system by dosing the external main manual shutoff valve and
slightly opening the ground-joint union.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal iniury,
death and/or property damage.
-Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
-Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections.
-Use proper length of pipe to avoid stress on gas control
manifold.
-If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at
furnace gas valve and extend a minimum of 2 in. (51 mm)
outside furnace casing.
-If codes allow a flexible connector, always use a new
connector, do not use a connector which has previously
serviced another gas appliance.
8. Check for gas leaks at the field-installed and
factory-installed gas lines after all piping connections have
been completed. Use a commercially available soap solution
made specifically for the detection of leaks (or method
specified by local codes and/or regulations).
Step 9-- Install Duct Connections
The unit has duct flanges on the supply- and return-air openings
on the side and bottom of the unit. For downshot applications, the
ductwork connects to the roof curb (See Fig. 2 and 3 for
connection sizes and locations).
Configuring Units for Downflow (Vertical) Discharge
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal iniury
or death.
Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch. Tag the disconnect switch with a suitable warning
label.
1. Open all electrical disconnects before starting any servace
work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)
3. Using Fig. 9 as a guide, proceed to cut out the downflow
duct panels.
4. Drill 1/2 in. (13 mm) diameter or larger holes in all four
corners of duct panels.
NOTE: On large chassis units remove sheet metal shields on
panels by using a crew driver to shear off retainers and discard.
5. On left and side supply duct opening side with keyhole or
single bladed hacksaw cut out panel along "V" groove.
6. On right side, with keyhole or single blade hacksaw, with
teeth facing up and starting from the front and moving to
the rear, cut along "V" groove.
7. Now with three sides cut, flex panel up and down to re-
move.
8. Replace side access panel and duct cover.
9. After completing unit conversion, perform all safety checks
and power up unit.
Alternate Method
1. Open all electrical disconnects and install lockout tag before
starting any service work.
2. Remove horizontal (metal) ductcovers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)
3. Leave top shipping crate on unit during this method.
4. Tip unit over on the front side (access panels) so the bottom
of the base pan is accessible.
5. Drill two holes diagonally opposed, of suitable size to ac-
commodate jigsaw or reciprocating saw. (See Fig. 9.)
NOTE: On large chassis units remove sheet metal shields on
panels by using a screw driver to shear off retainers and discard.
[]NIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the
unit being installed.
When cutting duct panels, do not contact or damage any
internal components (heat exchanger, electric heat). Do not
use a saw blade that protrudes more than 1 in. (25 mm) into
unit.
g
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PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in property damage.
Collect ALL screws that were removed. Do not leave screws
on rooftop as permanent damage to the roof may occur.
6. Using a suitable saw cut along "V" groove and remove duct
panels.
7. Tip unit back onto its base and replace duct covers.
8. After completing unit conversion, perform all safety checks
and power up unit.
NOTE: The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
nonresidence-type air conditioning and ventilating systems, NFPA
90A or residence-type, NFPA 90B; and/or local codes and
ordinances.
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Units are shipped for horizontal duct installation (by
removing duct covers).
2. Select and size ductwork, supply-air registers, and
return-air grilles according to American Society of Heating,
Refrigeration and Air Conditioning Engineers (ASHRAE)
recommendations.
3. Use flexible transition between rigid ductwork and unit to
prevent transmission of vibration. The transition may be
screwed or bolted to duct flanges. Use suitable gaskets to
ensure weather tight and airtight seal.
4. All units must have field-supplied filters or accessory filter
rack installed in the return-air side of the unit.
Recommended sizes for filters are shown in Table 1.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.
Table 1 - Physical Data - Unit 48VT-A
Unit Size 24040 24060 30040 30060 36060 36090
Nominial Capacity -ton 2 2 2.5 2.5 3 3
Shipping Weight (Ib) 354 354 346 346 426 426
(kg) 161 161 157 157 193 193
Compressor Quantity 1
Type Scroll
Refrigerant R- 41 OA
Refrigerant Quantity (Ib) 11.1 11.1 10.3 10.3 9.9 9.9
Quantity (kg) 5.0 5.0 4.7 4.7 4.5 4.5
Refrigerant Metering Device Indoor TXV, Outdoor Dual Accuraters
Orofice OD (in) 0.032 (2) 0.032 (2) 0.037 (2) 0.037 (2) 0.038 (2) 0.038 (2)
(mm) 0.81 (2) 0.81 (2) 0.94 (2) 0.94 (2) 0.97 (2) 0.97 (2)
Outdoor Coil
Rows... Fins/in, 2...21 2...21 2...21 2...21 2...21 2...21
face area (sq. ft.) 13.6 13.6 13.6 13.6 13.6 13.6
Outdoor Fan
Nominal Airflow (cfm) 2500 2500 2700 2700 31 O0 31 O0
Diameter (in.) 24 24 24 24 26 26
Diameter (mm) 610 610 610 610 660 660
Motor hp (rpm) 1/10 (810) 1/10 (810) 1/5 (810) 1/5 (810) 1/5 (810) 1/5 (810)
Indoor Coil
Rows... Fins/in, 3...17 3...17 3...17 3...17 3...17 3...17
face area (sq. ft.) 3.7 3.7 3.7 3.7 4.7 4.7
Indoor Blower
Nominal Airflow (cfm) 800 800 1000 1000 1200 1200
Size (in.) lOx 10 lOx 10 lOx 10 lOx 10 11 x 10 11 x 10
Size (mm) 254 x 254 254 x 254 254 x 254 254 x 254 279 x 254 279 x 254
Motor hp 1/2 1/2 1/2 1/2 3/4 3/4
Furnace Section*
Burner Orifice
Natural Gas Qty...Drill Size 2...44 2...38 2...44 2...38 2...38 3...38
Propane Gas Qty...Drill Size 2...55 2...53 2...55 2...53 2...53 3...53
High Pressure Switch (psig)
Cutout 650 +/- 15
Reset (Auto) 420 +/- 25
Loss- of- Charge/Low Pressu re Switch (psig)
Cutout 20 +/- 5
Reset (Auto) 45 +/- 10
Return Air Filtersl-$
disposable (in) 20x20x1 20x24x1 24x30x1
(mm) 508x508x25 508x610x25 610x762x25
*Based on altitude of 0 to 2000 ft (0-610 m).
1-Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of
300 ft/minute for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 IN. W.C.
:l: If using accessory filter rack refer to filter rack installation instructions for correct filter size and quantity.
10
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UnitSize
NominialCapacity- ton
ShippingWeight(Ib)
(kg)
CompressorQuantity
Type
Refrigerant
RefrigerantQuantity(Ib)
Quantity(kg)
RefrigerantMeteringDevice
OroficeOD(in)
(mm)
OutdoorCoil
Rows...Fins/in,
facearea(sq.ft.)
OutdoorFan
NominalAirflow(cfm)
Diameter(in.)
Diameter(mm)
Motorhp
Motor(rpm)
IndoorCoil
Rows...Fins/in,
facearea(sq.ft.)
IndoorBlower
NominalAirflow(cfm)
Size(in.)
Size(mm)
Motorhp
FurnaceSection*
BurnerOrifice
NaturalGasQty...DrillSize
PropaneGasQty...DrillSize
HighPressureSwitch(psig)
Cutout
Reset(Auto)
Loss-of-Charge/LowPressure
Switch(psig)
Cutout
Reset(Auto)
ReturnAirFiltersl-$
disposable(in)
(mm)
Table 1 - Physical Data - Unit 48VT-A Cont'd)
42080 42090 48090 48115 48130 80090 80115 80130
3.5 3.5 4 4 4 5 5 5
472 472 460 460 460 506 506 506
214 214 209 209 209 230 230 230
1
Scroll
R- 410A
11.3 11.3 12.5 12.5 12.5 15.2 15.2 15.2
5.1 5.1 5.7 5.7 5.7 6.9 6.9 6.9
Indoor TXV, Outdoor Dual Accuraters
0.040 (2) 0.040 (2) 0.040 (2) 0.040 (2) 0.040 (2) 0.049 (2) 0.049 (2) 0.049 (2)
1.02 (2) 1.02 (2) 1.02 (2) 1.02 (2) 1.02 (2) 1.24 (2) 1.24 (2) 1.24 (2)
2...21 2...21 2...21 2...21 2...21 2...21 2...21 2...21
17.5 17.5 17.5 17.5 17.5 23.3 23.3 23.3
31 O0
26
660
1/5
(81o)
31 O0
26
660
1/5
(81o)
31 O0
26
660
1/5
(81o)
31 O0
26
660
1/5
(81o)
31 O0
26
660
1/5
(81o)
3500
26
660
1/4
(81O)
3500
26
660
1/4
(81O)
3500
26
660
1/4
(81O)
3...17 3...17 3...17 3...17 3...17 3...17 3...17 3...17
4.7 4.7 5.6 5.6 5.6 5.6 5.6 5.6
1400 1400 1600 1600 1600 1750 1750 1750
11 xlO 11 xlO 11 xlO 11 xlO 11 xlO 11 xlO 11 xlO 11 xlO
279 x 254 279 x 254 279 x 254 279 x 254 279 x 254 279 x 254 279 x 254 279 x 254
3/4 3/4 1 1 1 1 1 1
2...38 3...38 3...38 3...33 3...31 3...38 3...33 3...31
2...53 3...53 3...53 3...51 3...49 3...53 3...51 3...49
650 +/- 15
420 +/- 25
20 +/- 5
45 +/- 10
24x30x1 24x36x1
610x762x25 610x914x25
*Based on altitude of 0 to 2000 ft (0-610 m).
1-Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of
300 ft/minute for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 IN. W.C.
:l: If using accessory filter rack refer to filter rack installation instructions for correct filter size and quantity.
11
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Horizontal Duct Covers
Basepan
Downflow
(Vertical)
Supply _
Knockout
J
A09076
Basepan
Downflow
J (Vertical)
Return
Knockout
Fig. 8 - Supply and Return Duct Opening
A09077
L)
Cut along
"V" grooves N
,Q
I
I I
Return Duct Panels
I-.IE
G
,IAIEIxli
: I sl AI Cl ','_
Itl HI,:
I !
Supply Duct Panels
,,7_ Cut along
'V" grooves
"_4 Drill
places
Flex up & down
to remove
Cut along "V"
I groove, teeth
facing up
--Drill 3 places
Drill 2 places
Cut along
"V" grooves
Return & Supply Duct Panels from
Underside of Base (Alternate Method)
A09420
Fig. 9-Vertical (Downflow) Discharge Duct Knockouts
Table 2 -Maximum Gas Flow Capacity*
NOMINAL INTERNAL LENGTH OF PIPE, FT (m)t
IRON DIAMETER 10 20 30 40 50 80 70 80 90 100 125 150 175 200
PIPE, SIZE (IN.) (3.0) (6.1) (9.1) (12.2) (15.2) (18.3) (21.3) (24.4) (27.4) (30.5) (31.1) (45.7) (53.3) (61.0)
(IN.)
1/2 .622 175 120 97 82 73 66 61 57 53 50 44 40 -- --
3/4 .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
1- 1/4 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280
1- 1/2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5-IN. W.C. (based on a 0.60 specific gravity gas). Refer to Table 2
and the NFGC NFPA 54/ANSI Z 223.1.
1-This length includes an ordinary number of fittings.
Table 3-Heating Inputs
GAS SUPPLY PRESSURE (IN. W.C.)
HEATING INPUT
(BTUH)
NUMBER OF
ORIFICES
40,000 2
60,000 2
90,000 3
115,000 3
130,000 3
Min
4.0
4.0
4.0
4.0
4.0
Naturalt
Max
13.0
13.0
13.0
13.0
13.0
Propane*t
Min Max
11.0 13.0
11.0 13.0
11.0 13.0
11.0 13.0
11.0 13.0
MANIFOLD PRESSURE
(IN. W.C.)
Natural1-
3.2-3.8
3.2-3.8
3.2-3.8
3.2-3.8
3.2-3.8
Propane*t
10.0-11.0
10.0-11.0
10.0-11.0
10.0-11.0
10.0-11.0
*When a unit is converted to propane, different size orifices must be used. See separate, natural-to-propane conversion kit instructions.
1-Based on altitudes from sea level to 2000 ft (610 m) above sea level. In the U.S.A. for altitudes above 2000 ft (610 m), reduce input rating 4 percent for each
additional 1000 ft (305 m) above sea level. In Canada, from 2000 ft (610 m) above sea level to 4500 ft (1372 m) above sea level, derate the unit 10 percent.
12
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6. Adequately insulate and weatherproof all ductwork located
outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest issue
of Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
of America (ACCA) minimum installation standards for
heating and air conditioning systems. Secure all ducts to
building structure.
7. Flash, weatherproof, and vibration-isolate all openings in
building structure in accordance with local codes and good
building practices.
Step 10 -- Install Electrical Connections
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal iniury
or death.
The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduit approved for electrical ground when
installed in accordance with NEC, NFPA 70 National Fire
Protection Association (latest edition) (in Canada, Canadian
Electrical Code CSA C22.1) and local electrical codes.
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the unit
being installed.
1. Make all electrical connections in accordance with NEC
NFPA 70 (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical
connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable
local codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high-voltage power to unit is within
operating voltage range indicated on unit rating plate. On
3-phase units, ensure phases are balanced within 2
percent. Consult local power company for correction of
improper voltage and/or phase imbalance.
4. Insulate low-voltage wires for highest voltage contained
within conduit when low-voltage control wires are in
same conduit as high-voltage wires.
5. Do not damage internal components when drilling
through any panel to mount electrical hardware, conduit,
etc.
Hi,h-Voltage Connections
When routing power leads into unit, use only copper wire between
disconnect and unit. The high voltage leads should be in a conduit
until they enter the duct panel; conduit termination at the duct
panel must be watertight.
The unit must have a separate electrical service with a
field-supplied, waterproof disconnect switch mounted at, or within
sight from, the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit
amps (ampacity) for wire sizing.
The field-supplied disconnect switch box may be mounted on the
unit over the high-voltage inlet hole when the standard power and
low-voltage entry points are used (See Fig. 2 and 3 for acceptable
location).
See unit wiring label (Fig. 15 and 16) and Fig. 10 for reference
when making high voltage connections. Proceed as follows to
complete the high-voltage connections to the unit.
Single phase units:
1. Run the high-voltage (L1, L2) and ground lead into the
control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side
of the contactor.
4. Connect field LI to black wire on connection 11 of the
compressor contactor.
5. Connect field wire L2 to yellow wire on connection 23 of
the compressor contactor.
Three-phase units:
1. Run the high-voltage (L1, L2, L3) and ground lead into the
control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side
of the contactor.
4. Connect field LI to black wire on connection 11 of the
compressor contactor.
5. Connect field wire L3 to yellow wire on connection 13 of
the compressor contactor.
6. Connect field wire L2 to blue wire from compressor.
Special Procedures for 208-V Operation
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal iniury
or death.
Make sure the power supply to the unit is switched OFF before
making any wiring changes. Tag the disconnect switch with a
suitable warning label. With disconnect switch open, move
black wire from transformer (3/16 in.) terminal marked 230 to
terminal marked 200. This retaps transformer to primary
voltaye of 208 vac.
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal iniury
or death.
Before making any wiring changes, make sure the gas supply
is switched off first. Then switch off the power supply to the
unit and install lockout tag.
Control Voltage Connections
Do not use any type of power-stealing thermostat. Unit control
problems may result.
Use no. 18 American Wire Gage (AWG) color-coded, insulated
(35°C minimum) wires to make the control voltage connections
between the thermostat and the unit. If the thermostat is located
more than 100 ft (30.5 m) from the unit (as measured along the
control voltage wires), use no. 16 AWG color-coded, insulated
(35 ° C minimum) wires.
Locate the seven (eight on 3-phase) low voltage thermostat leads
in 24 volt splice box. See Fig. 10 for connection diagram. Run the
low-voltage leads from the thermostat, through the control wiring
inlet hole grommet (Fig. 2 and 3), and into the low-voltage splice
box. Provide a drip loop before running wires through panel.
Secure and strain relief all wires so that they do not interfere with
13
H
![](asset-e.png)
operation of unit. A gray wire is standard on 3-phase unit for
connection to an economizer.
HIGH VOLTAGE |
POWER LEADS do,,. m
(SEE UNIT WIRINGI
LABEL) _
E__ --
EQUIP GR
CONTROL BOX
LOW VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)
Co-
IO-
IO-
-"l O,,.
io-
1o-
io=
I
FIELD-SUPPLIED
FUSED DISCONNECT
_WH_..TLW_I).D.
.,,YEL_._),.,,, ,_
GROG20.
RED, R)..
.BR_C) 9.
ORN_(O_)
BLU (DH)_,,
E_ E_ D
I
@
®
@
THERMOSTAT
(TYPICAL)
©
®
49
3_Phast
Only
SPLICE BOX
A09067
Fig. 10 -High and Control-Voltage Connections
Balance Point Setting-Thermidistat or Hybrid
Thermostat
BALANCE POINT TEMPERATURE-The "balance point"
temperature is a setting which affects the operation of the heating
mode. This is a field-selected input temperature (range 5 to 55°F)
(-15 to 12°C) where the Thermidistat or dual fuel thermostat will
monitor outdoor air temperature and decide whether to enable or
disable the heat pump. If the outdoor temperature is above the
"balance point", the heat pump will energize first to try to satisfy
the indoor temperature demand. If the heat pump does not make a
sufficient improvement within a reasonable time period (i.e. 15
minutes), then the gas furnace will come on to satisfy the indoor
temperature demand. If the outdoor temperature is below the
"balance point", the heat pump will not be allowed to operate (i.e.
locked out), and the gas furnace will be used to satisfy the indoor
temperature. There are three separate concepts which are related to
selecting the final "balance point" temperature. Read each of the
following carefully to determine the best "balance point" in a
hybrid installation:
1. Capacity Balance Temperature: This is a point where the
heat pump cannot provide sufficient capacity to keep up
with the indoor temperature demand because of declining
outdoor temperature. At or below this point, the furnace is
needed to maintain proper indoor temperature.
2. Economic Balance Temperature: Above this point, the heat
pump is the most cost efficient to operate, and below this
point the furnace is the most cost efficient to operate. This
can be somewhat complicated to determine and it involves
knowing the cost of gas and electricity, as well as the
efficiency of the furnace and heat pump. For the most
economical operation, the heat pump should operate above
this temperature (assuming it has sufficient capacity) and the
furnace should operate below this temperature.
3. Comfort Balance Temperature: When the heat pump is
operating below this point, the indoor supply air feels
uncomfortable (i.e. too cool). This is purely subjective and
will depend on the homeowner's idea of comfort. Below
this temperature the gas furnace should operate in order to
satisfy the desire for indoor comfort.
Transformer Protection
The transformer is of the energy-limiting type. It is set to withstand
a 30-sec. overload or shorted secondary condition. If an overload
or short is present, correct overload condition and check for blown
fuse on gas control board or Interface Fan Board. Replace fuse as
required with correct size and rating.
PRE-START-UP
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal iniury,
death or property damage.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Do not operate compressor or provide any electric power
to unit unless compressor terminal cover is in place and
secured.
3. Do not remove compressor terminal cover until all
electrical sources are disconnected and tagged.
4. Relieve and recover all refrigerant from system before
touching or disturbing anything inside terminal box if
refrigerant leak is suspected around compressor
terminals.
5. Never attempt to repair soldered connection while
refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective goggles and
proceed as follows:
a. Shut off electrical power to unit and install lockout
tag.
b. Relieve and reclaim all refrigerant from system
using both high- and low-pressure ports.
c. Cut component connecting tubing with tubing
cutter and remove component from unit.
d. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
Proceed as follows to inspect and prepare the unit for initial
start-up:
1. Remove access panels (see Fig. 19).
2. Read and follow instructions on all WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with, unit.
3. Make the following inspections:
a. Inspect for shipping and handling damages such as
broken lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections and
on unit base. Detecting oil generally indicates a
refrigerant leak.
c. Leak test all refrigerant tubing connections using
electronic leak detector, halide torch, or liquid-soap
solution. If a refrigerant leak is detected, see the Check
for Refrigerant Leaks section.
d. Inspect all field- and factory-wiring connections. Be
sure that connections are completed and tight.
e. Ensure wires do not touch refrigerant tubing or sharp
sheet metal edges.
f. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
14
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FIRE,EXPLOSIONHAZARD
Failuretofollowthiswarningcouldresultinpersonalinjury,
deathorpropertydamage.
Donotpurgegassupplyintothecombustionchamber.Donot
useamatchorotheropenflametocheckforgasleaks.Usea
commerciallyavailablesoapsolutionmadespecificallyfor
thedetectionofleakstocheckallconnections.
4.Verifythefollowingconditions:
a.Makesuregaslineisfreeofair.Beforelightingtheunit
forthefirsttime,performthefollowingwiththegas
valveinthe"OFF"position:
NOTE:If thegassupplypipewasnotpurgedbeforeconnecting
theunit,it willbefullofair.It isrecommendedthattheground
jointunionbeloosened,andthesupplylinebeallowedtopurge
untiltheodorof gasisdetected.Neverpurgegaslinesintoa
combustionchamber.Immediatelyupondetectionof gasodor,
retightentheunion.Allow5minutestoelapse,thenlightunit.
b.Makesurethatcondenser-fanbladeiscorrectly
positionedinfanorifice.Leadingedgeofcondenser-fan
bladeshouldbe1/2in.(12mm)maximumfromfan
orifice.
c.Makesurethatairfilter(s)isinplace.
d.Makesurethatcondensatedraintrapisfilledwithwater
toensureproperdrainage.
e.Makesurethatalltoolsandmiscellaneouslooseparts
havebeenremoved.
START-UP
Step 11 Check for Refrigerant Leaks
Proceed as follows to locate and repair a refrigerant leak and to
charge the unit:
1. Locate leak and make sure that refrigerant system pressure
has been relieved and reclaimed from both high- and
low-pressure ports.
2. Repair leak following Refrigerant Service procedures.
NOTE: Install a bi-flow filter drier whenever the system has been
opened for repair.
3. Add a small charge of R-410A refrigerant vapor to system
and leak-test unit.
4. Recover refrigerant from refrigerant system and evacuate to
500 microns if no additional leaks are not found.
5. Charge unit with Puron (R-410A) refrigerant, using an
electronic scale. Refer to unit rating plate for required
charge.
Step 2 1 Unit Sequence of Operation
48VT-A Sequence of Operation
a. CONTINUOUS FAN
(1.) Thermostat closes circuit R to G energizing the
blower motor for continuous fan.
b. COOLING MODE
(1.) If indoor temperature is above temperature set
point thermostat closes circuits R to G, R to Y and
R to O-The unit delivers cooling airfow.
c. HEAT PUMP HEATING MODE
Outdoor temperature above balance point setpoint of
thermostat.
(1.) On a call for heating, terminals "Y" and "G" of the
Hybrid thermostat are energized. The "Y" signal is
sent to the Defrost Board (DB) terminal "Y". The
DB has a built in five minute anti-short cycle timer
which will not allow the compressor to restart
before the time delay has expired.
(2.) "T2" energizes the compressor contactor via the
High Pressure Switch (HPS) and Low Pressure
Switch (LPS). The compressor and outdoor fan
start. Thermostat "G" energizes the Interface Fan
Board terminal "G". The blower motor is energized
through contacts of the IFB.
(3.) When the thermostat removes the "Y" and "G"
calls, the compressor contactor and outdoor fan are
de-energized. The evaporator motor is de-ener-
gized after a 90 sec. delay.
d. GAS HEATING MODE
Outdoor temperature below balance point setpoint of
thermostat.
Heating Sequence of Operation
(See Fig. 15 and 16 and unit wiring label.)
On a call for heating, terminal W of the thermostat is energized,
starting the induced-draft motor. When the pressure switch senses
that the induced-draft motor is moving sufficient combustion air,
the burner sequence begins. This function is performed by the
integrated gas unit controller (IGC). The indoor (evaporator)-fan
motor is energized 45 sec after flame is established. When the
thermostat is satisfied and W is de-energized, the burners stop
firing and the indoor (evaporator) fan motor shuts off after a
45-sec time-off delay. Please note that the IGC has the capability
to automatically reduce the indoor fan motor on delay and increase
the indoor fan motor off delay in the event of high duct static
and/or partially-clogged filter.
NOTE: An LED (light-emitting diode) indicator is provided on
the control board to monitor operation. The control board is
located by removing the burner access panel (see Fig. 19). During
normal operation, the LED is continuously on.
Step 31 Start-up Heating and Make Adjust-
ments
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the unit
being installed.
Complete the required procedures given in the Pre-Start-Up
section before starting the unit. Do not jumper any safety
devices when operating the unit.
Complete the required procedures given in the Pre-Start-Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Make sure that burner orifices are
properly aligned. Unstable operation nay occur when the burner
orifices in the manifold are misaligned.
Follow the lighting instructions on the heating section operation
label (located on the inside of the control access panel) to start the
heating section.
15
![](asset-10.png)
g
NOTE: Make sure that gas supply has been purged, and that all
gas piping has been checked for leaks.
"Manifold
A07679
Fig. 11 - Burner Assembly
BURNER FLAME
R
°'°
C99021
Fig. 12 - Monoport Burner
Check Heating Control
Start and check the unit for proper heating control operation as
follows (see furnace lighting instructions located on the inside of
the control access panel):
1. Place room thermostat SYSTEM switch in the HEAT
position and the fan switch is placed in AUTO position.
2. Set the heating temperature control of the thermostat above
room temperature.
3. The induced-draft motor will start.
4. On a call for heating, the main burner should light within 5
sec. of the spark being energized. If the burners do not light,
there is a 22-sec. delay before another 5-sec. try. If the
burners still do not light, this sequence is repeated. If the
burners do not light within 15 nfinutes from the initial call
for heat, there is a lockout. To reset the control, break the
24-v power to W.
5. The evaporator fan will turn on 45 sec. after the flame has
been established. The evaporator fan will turn off 45 sec.
after the thermostat has been satisfied. Please note that the
integrated gas unit controller (IGC) has the capability to
automatically reduce the evaporator "ON" delay and in-
crease the evaporator "OFF" delay in the event of high duct
static and/or partially-clogged filter.
Check Gas Input
Check gas input and manifold pressure after unit start-up (See
Table 3). If adjustment is required proceed as follows:
• The rated gas inputs shown in Table 3 are for altitudes from sea
level to 2000 ft (610 m) above sea level. These inputs are based
on natural gas with a heating value of 1025 Btu/ft 3 at 0.60
specific gravity, or propane gas with a heating value of 2500
Btu/ft 3 at 1.5 specific gravity.
IN THE U.S.A.:
The input rating for altitudes above 2,000 ft (610 m) must be
reduced by 4% for each 1,000 ft (305 m) at_ove see level.
For installations below 2,000 ft (610 m), refer to the unit rating
plate.
For installations above 2,000 ft (610 m) nmltiply the input by on
the rating plate by the derate multiplier in Table 4 for correct input
rate.
Table 4 - Altitude Derate Multiplier for U.S.A.*
DERATE MULTIPLIER
ALTITUDE FT (M) PERCENT OF DERATE FACTOR1-
0-2000 0 1,00
(0-610)
2001-3000* 8-12 0,90
(610-914)
3001-4000 12-16 0,86
(315-1219)
4001-5000 16-20 0,82
(1220 - 1524)
5001-6000 20-24 0.78
(1524-1829)
6001-7000 24-28 0.74
(1829 - 2134)
7001-8000 28-32 0.70
(2134-2438)
8001-9000 32-36 0,66
(2439-2743)
9001-10,000 36-40 0.62
(2744-3048)
In Canada see Canadian Altitude Adjustment.
1-Derate multiplier factors are based on midpoint altitude for altitude range.
IN CANADA:
The input rating for altitudes from 2,000 to 4,500 fl (610 m to
1372 m) above sea level must be derated 10% by an authorized
Gas Conversion Station or Dealer.
EXAMPLE:
90,000 Btu/hr Input Furnace Installed at 4300 fl (1311 m).
Furnace Input Rate at X Derate Multiplier =Furnace Input Rate at
Sea Level Factor Installation Altitude
g0,000 X 0.g0 = 81,000
When the gas supply being used has a different heating value or
specific gravity, refer to national and local codes, or contact your
distributor to deternfine the required orifice size.
[]NIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
and/or component life.
Do Not redrill an orifice. Improper drilling (burrs,
out-of-round holes, etc.) can cause excessive burner noise
and nfisdirection of burner flame. If orifice hole appears
damaged or it is suspected to have been redrilled, check
orifice hole with a numbered drill bit of correct size.
Adiust Gas Input
The gas input to the unit is determined by measuring the gas flow
at the meter or by measuring the manifold pressure. Measuring the
gas flow at the meter is recommended for natural gas units. The
manifold pressure must be measured to determine the input of
propane gas units.
Measure Gas Flow (Natural Gas []nits)
Minor ac[iustment to the gas flow can be made by changing the
manifold pressure. The manifold pressure must be maintained
between 3.2 and 3.8 IN. W.C.
16
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ON/OFF SWITCH
INLET
PRESSURE TAP
REGULATOR
PLASTIC
REGULATOR SPRING
(PROPANE - WHITE)
(NATURAL - SILVER)
GAS PRESSURE
MANIFOLD
A07751
Fig. 13 - Single-Stage Gas Valve
If larger adjustments are required, change main burner orifices
following the recommendations of national and local codes.
NOTE: All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.
Proceed as follows:
1. Turn off gas supply to unit.
2. Remove pipe plug on manifold (See Fig. 11) and connect
manometer. Turn on gas supply to unit.
3. Record number of seconds for gas meter test dial to make
one revolution.
4. Divide number of seconds in Step 3into 3600 (number of
seconds in one hr).
5. Multiply result of Step 4 by the number of cubic feet (cu fl)
shown for one revolution of test dial to obtain cubic feet (cu
fl) of gas flow per hour.
6. Multiply result of Step 5by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 3 (Consult the local gas
supplier if the heating value of gas is not known).
EXAMPLE: Assume that the size of test dial is 1 cu fl, one
revolution takes 32 sec, and the heating value of the gas is 1050
Btu/fl 3. Proceed as follows:
1. 32 sec. to complete one revolution.
2. 3600 + 32 = 112.5.
3. 112.5 x 1 =112.5 f13of gas flow/hr.
4. 112.5 x 1050 = 118,125 Btuh input.
If the desired gas input is 115,000 Btuh, only a minor change in the
manifold pressure is required.
Observe manifold pressure and proceed as follows to adjust gas
input:
1. Remove regulator cover screw over plastic adjustment
screw on gas valve (See Fig. 13).
2. Turn plastic adjustment screw clockwise to increase gas
input, or turn plastic adjustment screw counterclockwise to
decrease input (See Fig. 13). Manifold pressure must be
between 3.2 and 3.8 IN. W.C.
FIRE AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal
iniury or death and/or property damage.
Unsafe operation of the unit may result if manifold pressure
is outside this range.
3. Replace regulator cover screw on gas valve (See Fig. 13).
4. Turn off gas supply to unit. Remove manometer from
pressure tap and replace pipe plug on gas valve. (See Fig.
11.) Turn on gas to unit and check for leaks.
Measure Manifold Pressure (Propane Units)
Refer to propane kit installation instructions for properly checking
gas input.
NOTE: For installations below 2,000 fl (610 m), refer to the unit
rating plate for proper propane conversion kit. For installations
above 2,000 fl (610 m), contact your distributor for proper propane
conversion kit.
Check Burner Flame
With control access panel (see Fig. 19) removed, observe the unit
heating operation. Watch the burner flames to see if they are light
blue and soft in appearance, and that the flames are approximately
the same for each burner. Propane will have blue flame (See Fig.
12). Refer to the Maintenance section for information on burner
removal.
Normal Operation
An LED (light-emitting diode) indicator is provided on the
integrated gas unit controller (IGC) to monitor operation. The IGC
is located by removing the control access panel (see Fig. 19).
During normal operation, the LED is continuously on (See Table 5
for error codes).
Airflow and Temperature Rise
The heating section for each size unit is designed and approved for
heating operation within the temperature-rise range stamped on the
unit rating plate.
Table 10 shows the approved temperature rise range for each
heating input, and the air delivery cfm at various temperature rises
for a given external static pressure. The heating operation airflow
must produce a temperature rise that falls within the approved
range.
Refer to Indoor Airflow and Airflow Adjustments section to adjust
heating airflow when required.
Limit Switches
Normally closed limit switch (LS) completes the control circuit.
Should the leaving-air temperature rise above the maximum
allowable temperature, the limit switch opens and the control
circuit "breaks." Any interruption in the control circuit instantly
closes the gas valve and stops gas flow to the burners. The blower
motor continues to run until LS resets.
When the air temperature at the limit switch drops to the
low-temperature setting of the limit switch, the switch closes and
completes the control circuit. The direct-spark ignition system
cycles and the unit returns to normal heating operation.
Table 5-LED Indications
STATUS CODE LED INDICATION
Normal Operation 2On
No Power Hardware Failure Off
Limit Switch Fault 2 Flashes
Flame Sense Fault 3 Flashes
Four Consecutive Limit Switch Faults 4 Flashes
Ignition Lockout Fault 5 Flashes
Pressure Switch Fault 6 Flashes
Rollout Switch Fault 7 Flashes
Internal Control Fault 8 Flashes
Temporary 1 hr auto reset I 9 Flashes
NOTES:
1.This code indicates an internal processor fault that will reset itself in one
hr. Fault can be caused by stray RF signals in the structure or nearby. This
is a UL requirement.
2, LED indicates acceptable operation. Do not change ignition control
board,
3. When W is energized the burners will remain on for a minimum of 60 sec.
4. If more than one error mode exists they will be displayed on the LED in
sequence.
17
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g
Rollout Switch
The function of the rollout switch is to close the main gas valve in
the event of flame rollout. The switch is located above the main
burners. When the temperature at the rollout switch reaches the
maximum allowable temperature, the control circuit trips, closing
the gas valve and stopping gas flow to the burners. The indoor
(evaporator) fan motor (IFM) and induced draft motor continue to
run until switch is reset. The IGC LED will display FAULT CODE
7.
Step 4 -- Start-up Cooling and Make Adjust-
ments
Complete the required procedures given in the Pre-Start-Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Do not operate the compressor when the
outdoor temperature is below 40°F (4.4°C) (unless accessory
low-ambient kit is installed). Do not rapid-cycle the compressor.
Allow 5 minutes between on cycles to prevent compressor damage.
ChecMng Cooling Control Operation
Start and check the unit for proper cooling control operation as
follows:
1. Place room thermostat SYSTEM switch in OFF position.
Observe that blower motor starts when FAN switch is
placed in ON position and shuts down when FAN switch is
placed in AUTO position.
2. Place SYSTEM switch in COOL position and FAN switch
in AUTO position. Set cooling control below room
temperature. Observe that compressor, condenser fan, and
evaporator blower motors start. Observe that cooling cycle
shuts down when control setting is satisfied. The evaporator
fan will continue to run for 90 sec.
IMPORTANT: Three-phase, scroll compressors units are
direction oriented. Unit must be checked to ensure proper
compressor 3-phase power lead orientation. If not corrected within
5 minutes, the internal protector will shut off the compressor. The
3-phase power leads to the unit must be reversed to correct
rotation. When turning backwards, the difference between
compressor suction and discharge pressures will be near zero.
ChecMn_ and Adiustin_ Refrigerant Charge
The refrigerant system is fully charged with Puron® (R-410A)
refrigerant and is tested and factory sealed. Allow system to operate
a minimum of 15 minutes before checking or adjusting charge.
NOTE: Adjustment of the refrigerant charge is not required unless
the unit is suspected of not having the proper Puron® (R-410A)
charge.
The charging label and the tables shown refer to system
temperatures and pressures in cooling mode only. A refrigerant
charging label is attached to the inside of the compressor access
panel (see Fig. 19). The chart includes the required liquid line
temperature at given discharge line pressures and outdoor ambient
temperatures.
An accurate thermocouple- or thermistor-type thermometer, and a
gauge manifold are required when using the subcooling charging
method for evaluating the unit charge. Do not use mercury or small
dial-type thermometers because they are not adequate for this type
of measurement.
[]NIT DAMAGE HAZARD
Failure to follow this caution may result in unit damage.
When evaluating the refrigerant charge, an indicated
adjustment to the specified factory charge must always be
very minimal. If a substantial adjustment is indicated, an
abnormal condition exists somewhere in the cooling system,
such as insufficient airflow across either coil or both coils.
Proceed as follows:
1. Remove caps from low- and high-pressure service fittings.
2. []sing hoses with valve core depressors, attach low- and
high-pressure gauge hoses to low- and high-pressure
service fittings, respectively.
3. Start unit in Cooling Mode and let unit run until system
pressures stabilize.
4. Measure and record the following:
a. Outdoor ambient-air temperature (°F (°C) db).
b. Liquid line temperature (°F (°C).
c. Discharge (high-side) pressure (psig).
d. Suction (low-side) pressure (psig) (for reference only).
5. Using "Cooling Charging Charts," compare outdoor-air
temperature(°F (°C) db) with the discharge line pressure
(psig) to determine desired system operating liquid line
temperature (See Fig. 17).
6. Compare actual liquid line temperature with desired liquid
line temperature. Using a tolerance of - 2°F (-1.1°C), add
refrigerant if actual temperature is more than 2°F (1.1°C)
higher than proper liquid line temperature, or remove
refrigerant if actual temperature is more than 2°F (1.1°C)
lower than required liquid line temperature.
NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to the Check for Refrigerant Leaks section.
Indoor Airflow and Airflow Adjustments
[]NIT OPERATION HAZARD
Failure to follow this caution may result in unit damage.
For cooling operation, the recommended airflow is 350 to
450 cfm for each 12,000 Btuh of rated cooling capacity. For
heating operation, the airflow must produce a temperature
rise that falls within the range stamped on the unit rating
plate.
NOTE: Be sure that all supply-and return-air grilles are open,
free from obstructions, and adjusted properly.
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal
iniury or death.
Before making any indoor wiring adjustments, shut off gas
supply. Then disconnect electrical power to the unit and
install lockout tag before changing blower speed.
This unit has independent fan speeds for gas heating and cooling.
In addition, this unit has the field-selectable capability to run two
different cooling fan speeds: A normal cooling fan speed (350~400
18
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CFM/Ton) and an enhanced dehumidification fan speed (As low as
320 CFM/Ton) for use with either a dehumidistat or a thermostat
that supports dehumidification.
This unit is factory-set up for use with a single cooling fan speed.
The cooling speed is marked "LOW" on the interface fan board
(IFB) (Fig. 14) . The factory-shipped settings are noted in Table
10. There are 3 additional speed tap wires available for use in
either gas heating or cooling (For color coding on the indoor fan
motor leads, see Table 6). The additional 3 speed tap wires are
shipped loose with vinyl caps and are located in the control box,
near the interface fan board (IFB) (Fig. 14).
Gas Heating Fan Speed Set-up
To change the gas heating speed:
1. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding). Table 10 shows the
temperature rise associated with each fan speed for a given
static pressure. Make sure that the speed chosen delivers a
temperature rise within the rise range listed on the unit
rating plate.
2. Remove the current speed tap wire from the "GAS HEAT"
terminal on the interface fan board (IFB) (Fig.14) and place
vinyl cap over the connector on the wire.
3. Connect the desired speed tap wire to the "GAS HEAT"
terminal on the interface fan board (IFB).
Single Cooling Fan Speed Set-up (Dehumidification
feature not used)
To change cooling speed:
1. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding). Add the wet coil
pressure drop in Table 8 to the system static to determine the
correct cooling airflow speed in Table 10 that will deliver
the nominal cooling airflow as listed in Table 1 for each
size.
2. Remove the current speed tap wire from the "LOW"
terminal on the interface fan board (IFB) (Fig. 14) and place
vinyl cap over the connector on the wire,
3. Connect the desired speed tap wire to the "LOW" terminal
on the interface fan board (IFB).
Two Cooling Fan Speeds Set-up (Dehumidification
feature used)
IMPORTANT: Dehumidification control must open control
circuit on humidity rise above set point,
Use of the dehumidification cooling fan speed requires use of
either a 24 VAC dehumidistat or a thermostat which includes
control of a 24 VAC dehumidistat connection. In either case, the
dehumidification control must open the control circuit on humidity
rise above the dehumidification set point. Dehumidification
controls are available with the reverse logic; these must not be
used.
1. Remove fan speed tap wire from the "LOW" terminal on
the interface fan board (IFB) (Fig. 14).
2. Determine correct normal cooling fan speed for unit and
application. Add the wet coil pressure drop in Table 8 to
the system static to determine the correct cooling airflow
speed in Table 10 that will deliver the nominal cooling
airflow as listed in Table 1 for each size.
3. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding) for the normal cooling
fan speed and place desired speed tap wire on "HIGH" on
the interface board.
4. Refer to airflow tables (Table 10) to determine allowable
speeds for the dehumidification cooling fan speed. In Table
10, speeds that are not allowed for dehumidification cooling
are shaded.
5. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding) for the dehumidification
cooling fan speed and place desired speed tap wire on the
"LOW" connection on the interface board (IFB). Verify
that static pressure is in the acceptable range for the speed
tap to be used for dehumidification cooling.
6. Use any spare vinyl plugs to cap any unused speed tap
wires.
NOTE: For heat pump operation, the recommended airflow is 350
to 450 CFM for each 12,000 Btuh of rated cooling capacity.
Continuous Fan Operation
When the DEHUM feature is not used, the continuous fan speed
will be the same as cooling fan speed. When the DEHUM feature
is used, the continuous fan will operate on IFB "LOW" speed
when the DH control lead is not energized, or IFB "HIGH" speed
when the DH lead is energized (see Fig. 14).
Table 6- Color Coding for Indoor Fan Motor Leads
Black =High Speed
Orange = Med-High Speed
Red = Med Speed
Pink = Med-Low Speed
Blue = Low Speed
19
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FILTER SIZE
in. (mm)
20X20X1
(508X508X25)
20X24X1
(506X610x25)
24X30X1
(610X762x25)
24X36X1
(610X914X25)
Unit Size 500
24
30
36
42
48
60
-o
P N
GAS
HEAT HIGH LOW COM
000o _
QC6 QC7 QC4 QC3
K2 K1
C
RL3 C8 R1L Q1
O D2 t'T"
°00051;o °c0
JM6 RI2
OILL C2 D6 D4 AB 5 _ F1
D5 D3 C3 ! R R[ 4
R2 R3 R5 R6
P2
'in !
JW2
JW4
Y R U C 24VAC
SSTZ-8 iwl P1
W2 Y2/ G Y!/ C R
DH ¥
Fig. 14 - Interface Fan Board (IFB)
A09058
Table 7-Filter Pressure Drop Table (IN. W.C.)
CFM
600 600 700 600 900 1000 1100 1200 1300 1400 1600 1600 1700 1600 1900 2000 2100 2200 2300
0.05 0.07 0.08 0.1 0.12 0.13 0.14 0.15 ...........
.... 0.09 0.10 0.11 0.13 0.14 0.15 0.16 ........
-- -- -- 0.04 0.05 0.06 0.07 0.07 0.08 0.09 0.1 ........
....... 0.06 0.07 0.07 0.08 0.09 0.09 0.10 0.11 0.12 0.13 0.14 0.14
600 700
0.06 0.07
Table 8 - 48VT-A Wet Coil Pressure Drop
Standard CFM (S.C.EM)
800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
0.08 0.09 0.1
0.12 0.15 0.19 0.23 0.27
0.07 0.11 0.18 0.26 0.35
0.04 0.07 0.1 0.15 0.21
0.11 0.14 0.17 0.22 0.28
0.1 0.17 0.23 0.31 0.36
Table 9 -Wet Coil Air Delivery (CFM) - Downflow -High Speed with 1-in. (25 mm) Filter and Economizer
UNIT SIZE EXTERNAL STATIC PRESSURE (in. W.C.)
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
36, 42 1612 1569 1527 1481 1451 1393 1351 1317 1278 1242
48 2298 2239 2180 2110 2044 1951 1862 1777 1697 1591
60 2298 2239 2180 2110 2044 1951 1862 1777 1697 1591
20
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Unit
48VT(-,N)A24040
48VT(-,N)A24060
48VT(-,N)A30040
Table 10 -Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge -Unit 48VT-A24-60
Heating Motor
Rise
Range Speed
30 - 60°F
(17 - 33°C)
25 - 55°F
(14 - 31°C)
30 - 60°F
(17 - 33°C)
Wire External Static Pressure (in. W.C.)
Color 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
CFM 754 650 _i _291
Heating Rise 40 46 56 NA NA NA NA NA NA
Low Blue (oF)
Heating Rise 22 26 31 NA NA NA NA NA NA
(oc)
CFM 85_ 777 675 59_
Med- Heating Rise 36 39 45 51 NA NA NA NA NA
Pink (OF)
Low Heating Rise 20 22 25 28 NA NA NA NA NA
(oc)
CFM 94_' 85_ 774 684 _6 i
Heating Rise 32 36 39 44 52 NA NA NA NA
Medium 2 Red (OF)
Heating Rise 18 20 22 25 29 NA NA NA NA
(oc)
CFM 840 759 667 _7
Med- Heating Rise 30 33 36 40 45 52 NA NA NA
High1 Orange (OF)
Heating Rise 17 18 20 22 25 29 NA NA NA
(oc)
CFM 12@_[ _1_6_: _69 88_ _[_,,,, 73:_ 640
Heating Rise ...........................................................................................................................................
High Black (OF) NA NA NA NA 31 34 37 41 47 il
Heating Rise
(oc) 21 23 26
CFM i
Heating Rise NA NA NA
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise 24 27 29 NA NA NA NA NA NA
(oc)
CFM
Heating Rise 36 38 40 43 46 50 54 NA NA
High 1 Black (OF)
Heating Rise 20 21 22 24 25 28 30 NA NA
(oc)
CFM t ,,_=it,,'t ,,_=it,,'t ,,_=it,, t,,_=it,,'
Heating Rise 41 47 55 NA NA NA NA NA NA
Low Blue (OF)
Heating Rise 23 26 31 NA NA NA NA NA NA
(oc)
CFM 973 887 823 t";--it ''
Med- Heating Rise 31 34 37 41 45 56 NA NA NA
Pink (oF)
Low 1 Heating Rise 17 19 20 23 25 31 NA NA NA
(oc)
CFM 954 881 800
Heating Rise 28 30 32 34 38 42 46 54 NA
Medium Red (OF)
Heating Rise 15 16 18 19 21 23 26 30 NA
(oc)
CFM 996 915 840
Med- Heating Rise NA NA 30 33 36 40 44 54 NA
High2 Orange (OF)
Heating Rise NA NA 17 18 20 22 24 30 NA
(oc)
CFM 'i86_
Heating Rise NA NA NA 30 31 34 37 41 48
High Black (OF)
Heating Rise NA NA NA 17 17 19 21 23 27
(oc)
NA NA NA NA 17 19
754 650 _29
NA NA NA NA NA NA
Low Blue
NA NA NA NA NA NA NA NA NA
85_ 777 675 591
Med- 52 NA NA NA NA NA NA NA NA
Pink
Low
29 NA NA NA NA NA NA NA NA
94_ 85_ 774 684 _6 _
47 52 NA NA NA NA NA NA NA
Medium 2 Red
26 29 NA NA NA NA NA NA NA
840:: 759 667
Med- 44 48 53 NA NA NA NA NA NA
High Orange
21
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Unit
48VT(-,N)A30060
48VT(-,N)A36060
48VT(-,N)A36090
Table 10 -Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge -Unit 48VT-A24-60 (Cont)
Heating Motor
Rise
Range Speed
25 -55°F
(14 -31°C)
25 - 55°F
(14 - 31°C)
35 - 65°F Medium 2
(19 -36°C)
Wire External Static Pressure (in. W.C.)
Color 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
CFM 74_ ;638
Heating Rise NA NA NA NA NA NA NA NA NA
Low Blue (oF)
Heating Rise NA NA NA NA NA NA NA NA NA
(oc)
CFM 973 887 823 780 [ 665 _38,,,,,[ 45_ i
Med- Heating Rise 46 50 54 NA NA NA NA NA NA
Pink (oF)
Low Heating Rise 25 28 30 NA NA NA NA NA NA
(oc)
CFM 1,O88['[ _Q23i 954 881 800 _23 [ 658",,, [563 _6_ i
Heating Rise 41 43 47 50 NA NA NA NA NA
Medium Red (OF)
Heating Rise 23 24 26 28 NA NA NA NA NA
(oc)
CFM _1_40}, 996 915 840 _[[, [687 56_ 480,,
Med- Heating Rise 39 42 45 49 53 NA NA NA NA
High2 Orange (OF)
Heating Rise 22 23 25 27 29 NA NA NA NA
(oc)
Heating Rise 37 39 41 44 46 50 55 NA NA
High 1 Black (OF)
Heating Rise 21 22 23 24 26 28 30 NA NA
(oc)
CFM 1176 1121 1079 1019 974
Heating Rise 38 40 41 44 46 48 51 54 NA
Low Blue (oF)
Heating Rise 21 22 23 24 25 27 28 30 NA
(oc)
CFM 1295 !_23_ 1182 1126 1075 1016
Med- Heating Rise 34 36 38 39 41 44 47 49 52
Pink (oF)
Low 1 Heating Rise 19 20 21 22 23 24 26 27 29
(oc)
CFM _$345 , !_28_:: !_23_ 1194 1140 1095 1027 974 !92_ "
Heating Rise 33 35 36 37 39 41 43 46 48
Medium 2 Red (OF)
Heating Rise 18 19 20 21 22 23 24 25 27
(oc)
CFM _150_ , !_452 : _4_3 ::: __i"[ _323i !_28:_:: !_23_ ! 1169 1130
Med- Heating Rise 30 31 31 33 34 35 36 38 39
High Orange (OF)
Heating Rise 16 17 17 18 19 19 20 21 22
(oc)
CFM }_ 05 [}_643
Heating Rise 26 27 28 28 29 30 31 32 33
High Black (OF)
Heating Rise 14 15 15 16 16 17 17 18 18
(oc)
CFM 1176 1121 1079 1019 974 !:"75
Heating Rise 58 61 63 NA NA NA NA NA NA
Low Blue (oF)
Heating Rise 32 34 35 NA NA NA NA NA NA
(oc)
CFM 1182 1126 1075 1016
Med- Heating Rise 53 55 58 60 63 NA NA NA NA
Pink (oF)
Low Heating Rise 29 31 32 34 35 NA NA NA NA
(oc)
CFM }_34_ , _282 _28_ 1194 1140 1095 1027 974
Heating Rise 51 53 55 57 60 62 NA NA NA
Red (oF)
Heating Rise 28 29 31 32 33 35 NA NA NA
(oc)
CFM _23 _282 ,}_28 1169 1130
Med- Heating Rise 45 47 48 50 51 53 55 58 60
High1 Orange (OF)
Heating Rise
(oc) 25 26 27 28 29 29 31 32 33
40 41 42 43 45 46 47 48 50
High Black
CFM
Heating Rise
(OF)
Heating Rise
(oc) 22 23 24 24 25 25 26 27 28
22
![](asset-17.png)
Unit
48VT(-,N)A42060
48VT(-,N)A42090
48VT(-,N)A48090
Table 10 -Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge -Unit 48VT-A24-60 (Cont)
Heating Motor
Rise
Range Speed
25 - 55°F
(14 - 31°C)
35 - 65°F
(19 - 36°C)
35 - 65°F
(19 - 36°C)
Wire External Static Pressure (in. W.C.)
Color 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
CFM 1295 1234 1182 1126 85
Heating Rise 34 36 38 39 41 44 47 49 52
Low 1 Blue (OF)
Heating Rise 19 20 21 22 23 24 26 27 29
(oc)
CFM 1345 1282 1235 1194 1140 !92_ "
Med- Heating Rise 33 35 36 37 39 41 43 46 48
Pink (oF)
Low Heating Rise 18 19 20 21 22 23 24 25 27
(oc)
CFM _150_ , !_452:1358 1323 1282 1234 1169 1130
Heating Rise 30 31 31 33 34 35 36 38 39
Medium Red (OF)
Heating Rise 16 17 17 18 19 19 20 21 22
(oc)
CFM _1_45 !_492:: _4_ _4_ 1362 1313 1278 1231 1188
Med- Heating Rise 29 30 31 31 33 34 35 36 37
High2 Orange (OF)
Heating Rise 16 17 17 17 18 19 19 20 21
(oc)
Heating Rise ................................................................................................................................................................................................................................................................................................................................................................
High Black (°F) 26 27 28 28 29 30 31 32 33 il
Heating Rise
(oc) 17 17 18 18
CFM [ 958 89_ [ 857:
Heating Rise NA NA NA NA
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise 24 25 26 27 28 29 30 31 32
(oc)
CFM _48_, _448 _ O_
Heating Rise 40 41 42 43 45 46 47 48 50
High Black (OF)
Heating Rise 22 23 24 24 25 25 26 27 28
(oc)
CFM 1430 1374 1327
Heating Rise 48 49 51 54 56 58 60 64 NA
Low Blue (OF)
Heating Rise 26 27 28 30 31 32 34 36 NA
(oc)
CFM 1445 1389 1341 1281 t_'28_ }_ , _ _072
Med- Heating Rise 47 49 51 53 55 57 60 63 NA
Pink (oF)
Low 1 Heating Rise 26 27 28 29 31 32 33 35 NA
(oc)
CFM 1558 1513 1474 1438 1404 1349
Heating Rise 41 42 42 44 45 46 47 48 50
Red (OF)
Heating Rise 23 23 24 24 25 26 26 27 28
(oc)
CFM
Med- Heating Rise NA NA NA NA NA 35 36 37 38
High Orange (OF)
Heating Rise NA NA NA NA NA 19 20 20 21
(oc)
CFM _74
Heating Rise NA NA NA NA NA NA NA 35 36
High Black (OF)
Heating Rise NA NA NA NA NA NA NA 19 20
(oc)
14 15 15 16 16
1295 1234 1182 1126
53 55 58 60 63
Low Blue
29 31 32 34 35 NA NA NA NA
1345 1282 1235 1194 1140 1,095 1,02_ _74 92_
Med- 51 53 55 57 60 62 NA NA NA
Pink
Low 28 29 31 32 33 35 NA NA NA
_15Q_ , _452;: _4_ 1358 1323 1282 1234 1169 1130
45 47 48 50 51 53 55 58 60
Medium 1 Red
25 26 27 28 29 29 31 32 33
_4_ _4_ 1362 1313 1278 1231 1188
Med- 44 46 47 48 50 52 53 55 57
High2 Orange
Medium 2
23
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Unit
48VT(-,N)A48115
48VT(-,N)A48130
48VT(-,N)A60090
Table 10 -Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge -Unit 48VT-A24-60 (Cont)
Heating Motor
Rise
Range Speed
30 -60°F
(17 - 33°C)
35 - 65°F
(19 - 36°C)
35 - 65°F Medium 2
(19 - 36°C)
Wire External Static Pressure (in. W.C.)
Color 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
CFM 1430 1374 1327 12_; ;1223 _1_6 _1_2_ 1,O_ ;1,O_,6
Heating Rise 61 NA NA NA NA NA NA NA NA
Low Blue (oF)
Heating Rise 34 NA NA NA NA NA NA NA NA
(oc)
CFM 1445 1389 1341 1281 1236 _1_89 i _1_9 1Q2_
Med- Heating Rise 60 NA NA NA NA NA NA NA NA
Pink (oF)
Low Heating Rise 33 NA NA NA NA NA NA NA NA
(oc)
CFM 1558 1513 1474 1438 1404 1349
Heating Rise 52 53 54 56 57 59 60 NA NA
Medium 2 Red (OF)
Heating Rise 29 30 30 31 32 33 34 NA NA
(oc)
CFM _2_1 !2088,,,, _2Q65' _2Q13::: _98_i: i_785
Med- Heating Rise 41 42 42 43 44 45 46 47 49
High1 Orange (OF)
Heating Rise 23 23 23 24 24 25 26 26 27
(oc)
CFM 2_g_i: !2_40:, !2Q_::: !_68,
Heating Rise 35 36 37 38 40 41 42 44 46
High Black (OF)
Heating Rise 20 20 21 21 22 23 23 25 26
(oc)
CFM 1430 1374 1327 _1_6 _1_2_
Heating Rise NA NA NA NA NA NA NA NA NA
Low Blue (oF)
Heating Rise NA NA NA NA NA NA NA NA NA
(oc)
CFM 1445 1389 1341 1281 1236 _1_89 i _1_9 1Q2_
Med- Heating Rise NA NA NA NA NA NA NA NA NA
Pink (oF)
Low Heating Rise NA NA NA NA NA NA NA NA NA
(oc)
CFM 1558 1513 1474 1438 1404 1349
Heating Rise 57 59 60 62 64 65 NA NA NA
Medium 2 Red (OF)
Heating Rise 32 33 33 34 35 36 NA NA NA
(oc)
CFM _2Q65 _2Q13::: _98_i: i_785
Med- Heating Rise 45 46 47 48 49 50 51 52 54
High1 Orange (OF)
Heating Rise 25 26 26 27 27 28 28 29 30
(oc)
CFM _74
Heating Rise 39 40 41 42 44 45 47 49 51
High Black (OF)
Heating Rise 22 22 23 23 24 25 26 27 29
(oc)
Heating Rise 47 49 51 53 55 57 60 63 NA
Low 1 Blue (OF)
Heating Rise 26 27 28 29 31 32 33 35 NA
(oc)
CFM 1678 1635 1602 t_349
Med- Heating Rise 41 42 42 44 45 46 47 48 50
Pink (oF)
Low Heating Rise 23 23 24 24 25 26 26 27 28
(oc)
CFM 1843 1794 1753 1711 1675 1628
Heating Rise 35 36 36 37 38 39 40 41 42
Red (OF)
Heating Rise 19 20 20 20 21 22 22 23 23
(oc)
CFM
Med- Heating Rise NA NA NA NA NA 35 36 37 38
High Orange (OF)
Heating Rise NA NA NA NA NA 19 20 20 21
(oc)
CFM _74
Heating Rise NA NA NA NA NA NA NA 35 36
High Black (OF)
Heating Rise NA NA NA NA NA NA NA 19 20
(oc)
24
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Table 10 - Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge - Unit 48VT-A24-60 (Cont)
Unit
48VT(-,N)A60115
48VT(-,N)A60130
Heating Motor
Rise
Range Speed
30 - 60°F
(17 - 33°C)
35 - 65°F
(19 - 36°C)
Wire External Static Pressure (in. W.C.)
Color 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
CFM 1445 _389;; _1_3_ ;128_ ;1236 _1_89;; _1_9 1,0_ 1,02_
Heating Rise 60 NA NA NA NA NA NA NA NA
Low Blue (OF)
Heating Rise 33 NA NA NA NA NA NA NA NA
(oc)
CFM 1678 1635 1602 !_4 _ _ !_438,,,,, !_40_ _1_3_
Mad- Heating Rise 52 53 54 56 57 59 60 NA NA
Pink (oF)
Low Heating Rise 29 30 30 31 32 33 34 NA NA
(oc)
CFM !_ 880 t 1843 1794 1753 1711 1675 1628
Heating Rise 44 45 46 47 48 50 51 52 53
Medium 2 Red (OF)
Heating Rise 25 25 26 26 27 28 28 29 30
(oc)
CFM _2_1 !2088,,,, _2Q65' _2Q13::: _98_i: i_785
Mad- Heating Rise 41 42 42 43 44 45 46 47 49
High1 Orange (OF)
Heating Rise 23 23 23 24 24 25 26 26 27
(oc)
CFM _2_61 !2409 2_g_i: !2_40 :, !2Q_:: : !_68,
Heating Rise /
High Black (°F) 35 36 37 38 40 41 42 44 46
Heating Rise
(oc) 20 20 21 21 22 23 23 25 26
CFM 1445 _$389 _1_3_ 128_ :1236 _1_89 _1_9 1,02_
Heating Rise NA NA NA NA NA NA NA NA NA
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise 25 26 26 27 27 28 28 29 30
(oc)
CFM _74
Heating Rise 39 40 41 42 44 45 47 49 51
High Black (OF)
Heating Rise 22 22 23 23 24 25 26 27 29
(oc)
Low Blue
NA NA NA NA NA NA NA NA NA
1678 1635 1602 _1558 _15_3 _4_ :_4_ 140_ _1_3_9
Mad- 57 59 60 62 64 65 NA NA NA
Pink
Low 32 33 33 34 35 36 NA NA NA
_880:1843 1794 1753 1711 1675 1628
49 50 51 52 54 55 56 57 59
Medium 2 Red
27 28 28 29 30 31 31 32 33
_2_1 _2e88:_2e_5 _2e13:::_98_:: _785
Mad- 45 46 47 48 49 50 51 52 54
High1 Orange
* Air delivery values are without air filter and are for dry coil (See 48VT-A Wet Coil Pressure Drop table).
1 Factory-shipped gas heating speed
2 Factory-shipped heat pump speed
NA - Not allowed for gas heating speed
Note: Deduct field-supplied air filter pressure drop and wet coil pressure drop to obtain external static pressure available for ducting.
Shaded areas indicate speed/static combinations that are not permitted for dehumidification speed.
25
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A09268
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Fig. 16 - 208/230-3-60 Wiring Diagram, [:nit 48VT-A
A09284
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Fig. 17 - Cooling Charging Table-Subcooling
A09412
28
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MAINTENANCE
To ensure continuing high performance and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment. This combination
heating/cooling unit should be inspected at least once each year by
a qualified service person. To troubleshoot cooling or heating of
units, refer to Tables 10, 11 and 12.
NOTE: Consult your local dealer about the availability of a
maintenance contract.
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury
or death and unit component damage.
The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills, tools
and equipment. If you do not possess these, do not attempt to
perform any maintenance on this equipment, other than those
procedures recommended in the Owner's Manual.
ELECTRICALSHOCK HAZARD
Failure to follow these warnings could result in personal
iniury or death:
1. Turn off electrical power to the unit and install a lockout
tag before performing any maintenance or service on this
unit.
2. Use extreme caution when removing panels and parts.
3. Never place anything combustible either on or in contact
with the unit.
4. Should overheating occur or the gas supply fail to shut
off, turn off external main manual gas valve to the unit.
Then shut off electrical supply.
UNIT OPERATION HAZARD
Failure to follow this caution may result in improper
operation.
Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to
disconnecting when servicing.
The minimum maintenance requirements for this equipment are as
follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary. Certain geographical locations may require more
frequent inspections.
2. Inspect indoor coil, outdoor coil, drain pan, and condensate
drain each cooling season for cleanliness. Clean when
necessary.
3. Inspect blower motor and wheel for cleanliness at the
beginning of each heating and cooling season. Clean when
necessary. For first heating and cooling season, inspect
blower wheel bi-monthly to determine proper cleaning
frequency.
4. Check electrical connections for tightness and controls for
proper operation each heating and cooling season. Service
when necessary. Ensure electrical wiring is not in contact
with refrigerant tubing or sharp metal edges.
5. Check and inspect heating section before each heating
season. Clean and adjust when necessary.
6. Check flue hood and remove any obstructions, if necessary.
Air Filter
IMPORTANT: Never operate the unit without a suitable air filter
in the return-air duct system. Always replace the filter with the
same dimensional size and type as originally installed. (See Table 1
for recommended filter sizes.)
Inspect air filter(s) at least once each month and replace
(throwaway-type) or clean (cleanable-type) at least twice during
each heating and cooling season or whenever the filter(s) becomes
clogged with dust and/or lint.
Indoor Blower and Motor
NOTE: All motors are prelubricated. Do not attempt to lubricate
these motors.
For longer life, operating economy, and continuing efficiency,
clean accumulated dirt and grease from the blower wheel and
motor annually.
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect and tag electrical power to the unit before cleaning
the blower motor and wheel.
Cleaning the Blower Motor and Wheel
1. Remove and disassemble blower assembly as follows:
a. Remove blower access panel (see Fig. 19).
b. Disconnect 5pin plug and 4 pin plug from indoor
blower motor. Remove capacitor if required.
c. On all units, remove blower assembly from unit.
Remove screws securing blower to blower partition and
slide assembly out. Be careful not to tear insulation in
blower compartment.
d. Ensure proper reassembly by marking blower wheel and
motor in relation to blower housing before disassembly.
e. Loosen setscrew(s) that secures wheel to motor shaft.
Remove screws that secure motor mount brackets to
housing, and slide motor and motor mount out of
housing.
2. Remove and clean blower wheel as follows:
a. Ensure proper reassembly by marking wheel orientation.
b. Lift wheel from housing. When handling and/or
cleaning blower wheel, be sure not to disturb balance
weights (clips) on blower wheel vanes.
c. Remove caked-on dirt from wheel and housing with a
brush. Remove lint and/or dirt accumulations from
wheel and housing with vacuum cleaner, using soft
brush attachment. Remove grease and oil with mild
solvent.
d. Reassemble wheel into housing.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft. Reinstall blower into unit. Reinstall capacitor.
f. Connect 5pin plug and 4 pin plug to indoor blower
motor.
g. Reinstall blower access panel (see Fig. 19).
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.
H
29
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Integrated
Gas Unit
(IGC)
Auto Transformer
fuses used on 460
(Hidden)
Board (IFB)
Draft
Motor
Fan Partition Flue RoIIout
Mounting Collector Indu Burner Mounting Switch
Bracket Box Blower Rack Screw
Housing
Fig. 18 -Blower Housing and Flue Collector Box
A09199
Compressor
Access Panel
Blower
Access
Panel
Fig. 19 -Unit Access Panels
Control
Access
Panel
A09214
Induced Draft (combustion air) Blower Assembly
The induced-draft blower assembly consists of the inducer motor,
the blower housing, and the induced-draft blower wheel.
Clean periodically to assure proper airflow and heating efficiency.
Inspect blower wheel every fall and periodically during the heating
season. For the first heating season, inspect blower wheel
bimonthly to determine proper cleaning frequency.
To inspect blower wheel, remove draft hood assembly. Shine a
flashlight into opening to inspect wheel. If cleaning is required,
remove induced-draft blower assembly as follows:
1. Remove control access panel (See Fig. 19).
2. Remove the 5screws that attach induced-draft blower as-
sembly to the flue collector box cover.
3. Slide the assembly out of the unit. (See Fig. 20). Clean the
blower wheel. If additional cleaning is required, continue
with Steps 4 and 5.
4. To remove blower wheel, remove 2 setscrews.
5. To remove inducer motor, remove screws that hold the
inducer motor to the blower housing.
6. To reinstall, reverse the procedure outlined above.
Flue Gas Passageways
To inspect the flue collector box and upper areas of the heat
exchanger:
1. Remove the induced draft blower assembly according to
directions in the Induced Draft Blower Assembly section.
2. Remove the 11 screws holding the flue collector box cover
(See Fig. 18) to the heat exchanger assembly. Inspect the
heat exchangers.
3. Clean all surfaces, as required, using a wire brush.
Limit Switch
Remove blower access panel (see Fig. 19). Limit switch is located
on the fan partition.
Burner Ignition
Unit is equipped with a direct spark ignition 100 percent lockout
system. Ignition module (IGC) is located in the control box (See
Fig. 18). Module contains a self-diagnostic LED. During
servicing, refer to label diagram or Table 5 in these instructions for
LED interpretation.
If lockout occurs, unit may be reset by either momentarily
interrupting power supply to unit or by turning selector switch to
OFF position at the thermostat.
Main Burners
At the beginning of each heating season, inspect for deterioration
or blockage due to corrosion or other causes. Observe the main
burner flames and adjust, if necessary.
Removal of Gas Train
To remove the gas train for servicing:
1. Shut off main gas valve.
2. Shut off power to unit and install lockout tag.
3. Remove control access panel (See Fig. 19).
4. Disconnect gas piping at unit gas valve.
5. Remove fan partition mounting bracket (2 screws located
on the left side of control compartment on the fan partition
panel). Slide bracket forward, bottom first to remove. (See
Fig. 18).
6. Remove wires connected to gas valve. Mark each wire.
7. Remove ignitor and sensor wires at the ignitor module.
8. Remove the mounting screw that attaches the burner rack to
the unit base (See Fig. 18).
9. Slide the burner rack out of the unit (See Fig. 18 and 21).
10. To reinstall, reverse the procedure outlined above.
Outdoor Coil, Indoor Coil, and Condensate Drain Pan
Inspect the outdoor coil, indoor coil, and condensate drain pan at
least once each year. The coils are easily cleaned when dry;
therefore, inspect and clean the coils either before or after each
cooling season. Remove all obstructions, including weeds and
shrubs, that interfere with the airflow through the condenser coil.
Straighten bent fins with a fin comb. If coated with dirt or lint,
clean the coils with a vacuum cleaner, using the soft brush
attachment. Be careful not to bend the fins. If coated with oil or
grease, clean the coils with a mild detergent-and-water solution.
Rinse coils with clear water, using a garden hose. Be careful not to
splash water on motors, insulation, wiring, or air filter(s). For best
results, spray outdoor coil fins from inside to outside the unit. On
units with an outer and inner condenser coil, be sure to clean
between the coils. Be sure to flush all dirt and debris from the unit
base.
Inspect the drain pan and condensate drain line when inspecting
the coils. Clean the drain pan and condensate drain by removing all
foreign matter from the pan. Flush the pan and drain tube with
clear water. Do not splash water on the insulation, motor, wiring, or
3O
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airfilter(s).Ifthe drain tube is restricted, clear it with a "plumbers
snake" or similar probe device. Ensure that the auxiliary drain port
above the drain tube is also clear.
BLOWER
HOUSING
2 SETSCREWS
(HIDDEN)
C99085
Fig. 20 - Removal of Motor and Blower Wheel
Fig. 21 -Burner Rack Removed
FEEDERTUBE
STUB TUBE
A07680
DEFROST
THERMOSTAT
Fig. 22 - Defrost Thermostat Location
C99029
Outdoor Fan
UNIT OPERATION HAZARD
Failure to follow this caution may result in damage to unit
components.
Keep the outdoor fan free from all obstructions to ensure
proper cooling operation. Never place articles on top of the
unit.
1. Remove 6 screws holding outdoor grille and motor to top
cover.
2. Turn motor/grille assembly upside down on top cover to
expose the fan blade.
3. Inspect the fan blades for cracks or bends.
4. If fan needs to be removed, loosen the setscrew and slide the
fan off the motor shaft.
5. When replacing fan blade, position blade back to the same
position as before.
6. Ensure that setscrew engages the flat area on the motor shaft
when tightening.
7. Replace grille.
Electrical Controls and Wiring
Inspect and check the electrical controls and wiring annually. Be
sure to turn off the gas supply, and then the electrical power to the
unit.
Remove access panels (see Fig. 19) to locate all the electrical
controls and wiring. Check all electrical connections for tightness.
Tighten all screw connections. If any discolored or burned
connections are noticed, disassemble the connection, clean all the
parts, re-strip the wire end and reassemble the connection properly
and securely.
After inspecting the electrical controls and wiring, replace the
access panels (see Fig. 19). Start the unit, and observe at least one
complete heating cycle and one complete cooling cycle to ensure
proper operation. If discrepancies are observed in any operating
cycle, or if a suspected malfunction has occurred, check each
electrical component with the proper electrical instrumentation.
Refer to the unit wiring label when making these checkouts.
NOTE: Refer to the heating and/or cooling sequence of operation
in this publication as an aid in determining proper control
operation.
Refrigerant Circuit
Annually inspect all refrigerant tubing connections and the unit
base for oil accumulations. Detecting oil generally indicates a
refrigerant leak.
EXPLOSION, PERSONAL
ENVIRONMENTAL HAZARD INJURY AND
Failure to follow this warning could result in personal injury,
death or property damage.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal. Use all
service ports and open all flow-control devices, including
solenoid valves.
If oil is detected or if low cooling performance is suspected,
leak-test all refrigerant tubing using an electronic leak-detector,
halide torch, or liquid-soap solution. If a refrigerant leak is
detected, refer to the Check for Refrigerant Leaks section.
H
31
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If norefrigerantleaksarefoundandlowcoolingperformanceis
suspected,refertotheCheckingandAdjustingRefrigerantCharge
section.
Gas Input
The gas input does not require checking unless improper heating
performance is suspected. If a problem exists, refer to the Start-Up
section.
Indoor Airflow
The heating and/or cooling airflow does not require checking
unless improper performance is suspected. If a problem exists, be
sure that all supply- and return-air grilles are open and free from
obstructions, and that the air filter is clean. When necessary, refer to
the Indoor Airflow and Airflow Adjustments section to check the
system airflow.
Check Defrost Thermostat
The defrost thermostat is usually located on the lowest liquid
leaving circuit of the left condenser coil (see Fig. 22). The
thermostat closes at 32°F (0°C) and opens at 65°F (18°C).
Puron Items
Metering Device (Thermostatic Expansion Valve &
Piston)
This unit uses both a hard shutoff, balance port TXV in the indoor
coil and a piston in each side of the outdoor coil. The TXV
maintains a constant superheat at the evaporator coil exit (cooling
mode) resulting in higher overall system efficiency.
Pressure Switches
Pressure switches are protective devices wired into control circuit
(low voltage). They shut off compressor if abnormally high or low
pressures are present in the refrigeration circuit. These pressure
switches are specifically designed to operate with Puron (R-410A)
systems. R-22 pressure switches must not be used as replacements
for the Puron (R-410A) system.
Loss of Charge Switch
This switch is located on the liquid line and protects against low
suction pressures caused by such events as loss of charge, low
airflow across indoor coil, dirty filters, etc. It opens on a pressure
drop at about 20 psig. If system pressure is above this, switch
should be closed. To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have
continuity on a good switch.
NOTE: Because these switches are attached to refrigeration
system under pressure, it is not advisable to remove this device for
troubleshooting unless you are reasonably certain that a problem
exists. If switch must be removed, remove and recover all system
charge so that pressure gauges read 0 psi. Never open system
without breaking vacuum with dry nitrogen.
High-Pressure Switch
The high-pressure switch is located in the discharge line and
protects against excessive condenser coil pressure. It opens at 650
psig.
High pressure may be caused by a dirty outdoor coil, failed fan
motor, or outdoor air recirculation. To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have
continuity on a good switch.
Copeland Scroll Compressor (Puron Refrigerant)
The compressor used in this product is specifically designed to
operate with Puron (R-410A) refrigerant and cannot be
interchanged.
The compressor is an electrical (as well as mechanical) device.
Exercise extreme caution when working near compressors. Power
should be shut off, if possible, for most troubleshooting techniques.
Refrigerants present additional safety hazards.
EXPLOSION HAZARD
Failure to follow this warning could result in personal iniury
or death and/or property damage.
Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from
refrigerants and oils.
The scroll compressor pumps refrigerant throughout the system by
the interaction of a stationary and an orbiting scroll. The scroll
compressor has no dynamic suction or discharge valves, and it is
more tolerant of stresses caused by debris, liquid slugging, and
flooded starts. The compressor is equipped with an internal
pressure relief port. The pressure relief port is a safety device,
designed to protect against extreme high pressure. The relief port
has an operating range between 550 and 625 psi differential
pressure.
32
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Speedup
Pins Quiet
Shift Defrost interval
DIP switches
Fig. 23 - Defrost Control
A08020
33
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Fig. 24 - Refrigerant Circuit
C99097
OUTDOOR COIL
I
LEGEND
HPS - High Pressure Switch
LCS - Loss of Charge Switch
_ Accurater_'Metering Device
[-_ Arrow indicates direction of flow
r
Bypass
Position
TXV in Meterin
Position
r-q
LCS
Fig. 25 - Typical Heat Pump Operation, Cooling Mode
"__N DOO R COIL
C03011
34
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OUTDOOR COIL
1
LEGEND
HPS - High Pressure Switch
LCS - Loss of Charge Switch
_ _i_ Accurate¢_Meteiing Device
[] Arrow indicates direction of flow
Mete@g
Position
TXV in Bypass
Position
:[:='1
LCS
Fig. 26 - Typical Heat Pump Operation, Heating Mode
INDOOR COIL
J
C03012
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal iniury
or equipment damage.
This system uses Puron (R-410A) refrigerant which has
higher operating pressures than R-22 and other refrigerants.
No other refrigerant may be used in this system. Gauge set,
hoses, and recovery system nmst be designed to handle Puron.
If you are unsure, consult the equipment manufacturer.
Refrigerant System
This information covers the refrigerant system of the 48VT-A
including the compressor oil needed, servicing systems on roofs
containing synthetic materials, the filter drier and refrigerant
charging.
Compressor Oil
If additional oil is needed use Uniqema RL32-3MAF. If this oil is
not available, use Copeland Ultra 32CC or Mobil Artic EAL22CC.
This oil is extremely hygroscopic, meaning it absorbs water
readily. POE oils can absorb 15 times as nmch water as other oils
designed for HCFC and CFC refrigerants. Take all necessary
precautions to avoid exposure of the oil to the atmosphere.
Servicing Systems on Roofs and with Synthetic materials
POE (polyolester) compressor lubricants are known to cause long
term damage to some synthetic roofing materials.
Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one year or more.
When performing any service that may risk exposure of
compressor oil to the roof, take appropriate precautions to protect
roofing. Procedures which risk oil leakage include, but are not
limited to, compressor replacement, repairing refrigerant leaks,
replacing refrigerant components such as filter drier, pressure
switch, metering device, coil, accumulator, or reversing valve.
Synthetic Roof Precautionary Procedure
1. Cover extended roof working area with an in, permeable
polyethylene (plastic) drip cloth or tarp. Cover an
approximate 10xl0 fl (3x3 m) area.
2. Cover area in front of the unit service panel with a terry
cloth shop towel to absorb lubricant spills and prevent
run-offs, and protect drop cloth from tears caused by tools
or components.
3. Place terry cloth shop towel inside unit immediately under
component(s) to be serviced and prevent lubricant run-offs
through the louvered openings in the unit base.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per
local codes.
Liquid Line Filter Drier
This filter drier is specifically designed to operate with Puron. Use
only factory-authorized components. Filter drier must be replaced
whenever the refrigerant system is opened. When removing a filter
drier, use a tubing cutter to cut the drier from the system. Do not
unsweat a filter drier from the system. Heat from unsweating will
release moisture and contaminants from drier into system.
Puron (R-410A) Refrigerant Charging
Refer to unit information plate and charging chart. Some R-410A
refrigerant cylinders contain a dip tube to allow liquid refrigerant to
flow from cylinder in upright position. For cylinders equipped
with a dip tube, charge Puron units with cylinder in upright
position and a commercial metering device in manifold hose.
Charge refrigerant into suction-line.
TROUBLESHOOTING
Use the Troubleshooting Guides (See Tables 10-12) if problems
occur with these units,
START-UP CHECKLIST
Use Start-Up checklist to ensure proper start-up procedures are
followed.
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PURON® (R-410A) QUICK REFERENCE GUIDE
H "
• Puron refrigerant operates at 50-70 percent higher pressures than R-22. Be sure that servicing equipment and replacement
components are designed to operate with Puron
• Puron refrigerant cylinders are rose colored.
• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
• Puron systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when
charging into suction line with compressor operating
Manifold sets should be minimum 700 psig high side and 180 psig low side with 550 psig low-side retard.
Use hoses with minimum 700 psig service pressure rating.
Leak detectors should be designed to detect HFC refrigerant.
Puron, as with other HFCs, is only compatible with POE oils.
Vacuum pumps will not remove moisture from oil.
Do not use liquid-line filter driers with rated working pressures less than 600 psig.
Do not leave Puron suction line filter driers in line longer than 72 hrs.
Do not install a suction-line filter drier in liquid line.
POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
POE oils may cause damage to certain plastics and roofing materials.
Wrap all filter driers and service valves with wet cloth when brazing.
A factory approved liquid-line filter drier is required on every unit.
Do NOT use an R-22 TXV.
Never open system to atmosphere while it is under a vacuum.
When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter
driers. Evacuate to 500 microns prior to recharging.
• Do not vent Puron into the atmosphere.
• Observe all warnings, cautions, and bold text.
• All indoor coils must be installed with a hard shutoff Puron TXV metering device.
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Table11-Troubleshooting Guide - Cooling or Heat Pump Heating Mode
SYMPTOM
Compressor and Outdoor fan will not
start.
Compressor will not start but Outdoor
fan runs.
CAUSE
Power Failure
Fuse blown or circuit breaker tripped
Defective thermostat, contactor, transformer, or control
relay
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Faulty wiring or loose connections in compressor circuit
Compressor motor burned out, seized, or internal over-
load open
Defective run/start capacitor, overload, start relay
One leg of 3-phase power dead
Three-phase scroll compressor makes
excessive noise, and there may Scroll compressor is rotating in the wrong direction
be a low pressure differential.
Refrigerant overcharge or undercharge
Compressor cycles (other than normally
satisfying thermostat).
Compressor operates continuously.
Excessive head pressure.
Head pressure too low.
Excessive suction pressure.
Suction pressure too low.
Compressor runs but outdoor fan does
not
Defective compressor
Insufficient line voltage
Blocked Outdoor
Defective run/start capacitor, overload or start relay
Defective thermostat
Faulty Outdoor-fan motor or capacitor
Damaged reversing valve
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
Thermostat set too low
Low refrigerant charge
Mechanical damage in compressor.
Air in system
Frosted coil with incorrect defrost operation
Outdoor coil dirty or restricted
Dirty air filter
Dirty Indoor or Outdoor coil
Refrigerant overcharged
Air in system
Indoor or Outdoor air restricted or air short-cycling
Low refrigerant charge
Compressor IPR leaking
Restriction in liquid tube
High heat load
Compressor IPR leaking
Refrigerant overcharged
Reversing valve hung up or leaking internally
Dirty air filter
Low refrigerant charge
Metering device or low side restricted
Insufficient Indoor airflow
Temperature too low in conditioned area
Outdoor ambient below 55°F (12.8°C)
Field-installed filter-drier restricted
(Heat) Outdoor coil frosted
NC (normally closed) contacts on defrost board open
REMEDY
Call power company.
Replace fuse or reset circuit breaker.
Replace component.
Determine cause and correct.
Check wiring diagram and rewire correctly.
Lower thermostat setting below room temperature.
Check wiring and repair or replace.
Determine cause Replace compressor.
Determine cause and replace.
Replace fuse or reset circuit breaker. Determine
cause.
Correct the direction of rotation by reversing the
3-phase power leads to the unit.
Recover refrigerant, evacuate system, and recharge
to capacities shown on nameplate.
Replace and determine cause.
Determine cause and correct.
Determine cause and correct.
Determine cause and replace.
Replace thermostat.
Replace.
Determine cause and correct
Locate restriction and remove.
Replace filter.
Decrease load or increase unit size.
Reset thermostat.
Locate leak, repair, and recharge.
Replace compressor.
Recover refrigerant, evacuate system, and recharge.
Check defrost time settings, Reset as necessary
Check defrost temperature switch, Replace as nec-
essary
Clean coil or remove restriction.
Replace filter.
Clean coil.
Recover excess refrigerant.
Recover refrigerant, evacuate system, and recharge.
Determine cause and correct.
Check for leaks, repair, and recharge.
Replace compressor.
Remove restriction.
Check for source and eliminate.
Replace compressor.
Recover excess refrigerant.
Replace valve
Replace Filter.
Check for leaks, repair, and recharge.
Remove source of restriction.
Increase air quantity. Check filter -- replace if neces-
sary.
Reset thermostat.
Install low-ambient kit.
Replace.
Move timer on control board to 30 minutes between
defrost cycles
Check condition of relay on board Replace if neces-
sary
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Table 12 - Troubleshooting Guide-Heating
SYMPTOM CAUSE
Water in gas line
No power to furnace
No 24-v power supply to control circuit
Burners will not ignite Mis-wired or loose connections
Misaligned spark electrodes
No gas at main burners
Dirty air filter
Gas input to furnace too low
Unit undersized for application
Inadequate heating Restricted airflow
Limit switch cycles main burners
Incomplete combustion results in: Aldehyde odors,
carbon monoxide, sooting flame, floating flame
Poor flame characteristics
REMEDY
Drain. Install drip leg.
Check power supply fuses, wiring or circuit breaker.
Check transformer.
NOTE: Some transformers have internal over-current protection
that requires a cool-down period to reset.
Check all wiring and wire nut connections
Check flame ignition and sense electrode positioning.
Adjust as necessary.
1. Check gas line for air. Purge as necessary. NOTE: After purging
gas line of air, wait at least 5 minutes for any gas to dissipate be-
fore attempting to light unit.
2. Check gas valve.
Clean or replace filter as necessary
Check gas pressure at manifold match with that on unit nameplate
Replace with proper unit or add additional unit
Clean or replace filter. Remove any restriction.
Check rotation of blower, temperature rise of unit. Adjust as neces-
sary.
1. Tighten all screws around burner compartment
2. Cracked heat exchanger. Replace.
3. Unit over-fired. Reduce input (change orifices or adjust gas line
or manifold pressure).
4. Check burner alignment.
5. Inspect heat exchanger for blockage. Clean as necessary.
Table 13 -Troubleshooting Guide-LED Status Codes
SYMPTOM CAUSE REMEDY
Check 5-amp fuse son IGC*, power to unit, 24-v circuit breaker,
No Power Hardware failure and transformer. Units without a 24-v circuit breaker have an
(LED OFF) Loss of power to control module (IGC)*. internal overload in the 24-v transformer. If the overload trips,
allow 10 minutes for automatic reset.
Limit switch faults Check the operation of the indoor (evaporator) fan motor, Ensure
(LED 2 flashes) High temperature limit switch is open. that the supply-air temperature rise is in accordance with the
range on the unit nameplate. Clean or replace filters.
Flame sense fault The IGC* sensed flame that should not be present. Reset unit. If problem persists, replace control board.
(LED 3 flashes)
4 consecutive limit switch Check the operation of the indoor (evaporator) fan motor and that
faults Inadequate airflow to unit. supply-air temperature rise agrees with range on unit nameplate
(LED 4 flashes) information.
Ignition lockout Check ignitor and flame sensor electrode spacing, gaps, etc.
(LED 5 flashes) Unit unsuccessfully attempted ignition for 15 minutes. Ensure that fame sense and ignition wires are properly terminated.
Verify that unit is obtaining proper amount of gas.
Verify wiring connections to pressure switch and inducer motor.
Pressure Switch motor fault Verify pressure switch hose is tightly connected to both inducer
(LED 6 flashes) Open pressure switch, housing and pressure switch, Verify inducer wheel is properly
attached to inducer motor shaft. Verify inducer motor shaft is turn-
ing.
Rollout switch will automatically reset, but IGC will continue to
Rollout switch fault lockout unit. Check gas valve operation. Ensure that induced-draft
(LED 7 flashes) Rollout switch has opened, blower wheel is properly secured to motor shaft. Inspect heat
exchanger. Reset unit at unit disconnect.
Internal control fault Microprocessor has sensed an error in the software If error code is not cleared by resetting unit power, replace the
(LED 8 flashes) or hardware. IGC*.
Temporary I hr auto reset Reset 24-v. to control board or turn thermostat off, then on again.
(LED 9 flashes) Electrical interference impeding IGC software Fault will automatically reset itself in one (1) hour.
*WARNING .!_ : If the IGC must be replaced, be sure to ground yourself to dissipate any electrical charge that my be present before handling new control
board. The IGC is sensitive to static electricity and my be damaged if the necessary precautions are not taken.
IMPORTANT: Refer to Table 12-Troubleshooting Guide-Heating for additional troubleshooting analysis.
LEGEND
IGC--Integrated Gas Unit Controller
LED--Light-Emitting Diode
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I. PRELIMINARY INFORMATION
MODEL NO.:
SERIAL NO.:
DATE:
TECHNICIAN:
START-UP CHECKLIST
(Remove and Store in Job Files)
II. PRESTART-UP (Insert check mark in box as each item is completed)
()VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT
( ) REMOVE ALL SHIPPING HOLD DOWN BOLTS AND BRACKETS PER INSTALLATION INSTRUCTIONS
( ) CHECK ALL ELECTRICAL CONNECTIONS AND TERMINALS FOR TIGHTNESS
( ) CHECK GAS PIPING FOR LEAKS (WHERE APPLICABLE)
( ) CHECK THAT INDOOR (EVAPORATOR) AIR FILTER IS CLEAN AND IN PLACE
( ) VERIFY THAT UNIT INSTALLATION IS LEVEL
( ) CHECK FAN WHEEL, AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND SETSCREW TIGHTNESS
III. START-UP
ELECTRICAL
SUPPLY VOLTAGE
COMPRESSOR AMPS
INDOOR (EVAPORATOR) FAN AMPS
TEMPERATURES
OUTDOOR (CONDENSER) AIR TEMPERATURE
RETURN-AIR TEMPERATURE DB
COOLING SUPPLY AIR DB
HEAT PUMP SUPPLY AIR
GAS HEAT SUPPLY AIR
PRESSURES
GAS INLET PRESSURE
GAS MANIFOLD PRESSURE
REFRIGERANT SUCTION
REFRIGERANT DISCHARGE
( ) VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS
GAS HEAT TEMPERATURE RISE
TEMPERATURE RISE (See Literature) RANGE
MEASURED TEMPERATURE RISE
*Measured at suction inlet to compressor
1- Measured at liquid line leaving condenser.
DB
WB
WB
IN. W.C.
IN. W.C.
PSIG, SUCTION LINE TEMP*
PSIG, LIQUID TEMPi-
39
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Copyright 2009 Carrier Corp. • 7310 W. Morris St. • Indianapolis, IN 46231 Edition Date: 08/09
Manufacturer reserves the right to change, at any time, specification8 and design8 without notice and without obligations,
Catalog No: 48VT-06SI
Replaces: 48VT- 05Sl
4O