International comfort products PHD424 User manual

INSTALLATION INSTRUCTIONS
R−410A Single Package Heat Pumps
PHD424−60
1 & 3 Phase
These instructions must be read and understood completely before attempting installation
Safety Labeling and Signal Words
DANGER, WARNING, CAUTION, and NOTE
The signal words DANGER, WARNING,
CAUTION,and NOTE are used to identify levels
of hazard seriousness. The signal word DANGER
is only used on product labels to signify an
immediate hazard. The signal words WARNING,
CAUTION, and NOTE will be used on product
labels and throughout this manual and other
manual that may apply to the product.
DANGER −Immediate hazards which will result in
severe personal injury or death.
WARNING −Hazards or unsafe practices which
could result in severe personal injury or death.
CAUTION −Hazards or unsafe practices which
may result in minor personal injury or product or
property damage.
NOTE −Used to highlight suggestions which will
result in enhanced installation, reliability, or
operation.
!WARNING
Signal Words in Manuals
The signal word WARNING is used throughout
this manual in the following manner:
The signal word CAUTION is used throughout
this manual in the following manner:
!CAUTION
Signal Words on Product Labeling
Signal words are used in combination with
colors and/or pictures or product labels.
SAFETY CONSIDERATIONS 2.................
RECEIVING AND INSTALLATION 2.............
Step 1 −Check Equipment 2...................
Step 2 −Provide Unit Support 2.................
Step 3 −Provide Clearances 3..................
Step 4 −Rig and Place Unit 3...................
Step 5 −Install Duct Connections 7..............
Step 6 −Provide for Condensate Disposal 8......
Step 7 −Install Electrical Connections 9..........
Wiring Diagram 12.............................
PRE−START−UP 18............................
START−UP 18.................................
Step 1 −Check for Refrigerant Leaks 18..........
Step 2 −Start−Up Cooling Section and Make Adj. 18
Airflow Adjustments 19..........................
Maintenance 22................................
Troubleshooting 30.............................
Start−Up Checklist 33...........................
TABLE OF CONTENTS !WARNING
PERSONAL INJURY, AND/OR PROPERTY
DAMAGE HAZARD
Failure to carefully read and follow this warning
could result in equipment malfunction, property
damage, personal injury and/or death.
Installation or repairs made by unqualified
persons could result in equipment malfunction,
property damage, personal injury and/or death.
The information contained in this manual is
intended for use by a qualified service technician
familiar with safety procedures and equipped
with proper tools and test instruments.
Installation must conform with local building
codes and with the national Electrical Code
NFPA70 current edition or Canadian Electrical
Code part 1 CSA C.22.1.
518 01 2003 03
7−19−13

2518 01 2003 03
Fig. 1 −Unit PHD4
SAFETY CONSIDERATIONS
Installation and servicing of this equipment can be hazardous
due to mechanical and electrical components. Only trained and
qualified personnel should install, repair, or service this
equipment.
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations
must be performed by trained service personnel. When working
on this equipment, observe precautions in the literature, on tags,
and on labels attached to or shipped with the unit and other
safety precautions that may apply.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
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 Electrical Code (NEC) NFPA
70.
In Canada refer to the current editions of the Canadian Electrical
Code CSA C22.1.
Recognize safety information. This is the safety−alert symbol .
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury. Understand
these signal words: DANGER, WARNING, and CAUTION. These
words are used with the safety−alert symbol. DANGER identifies
the most serious hazards which will result in severe personal in-
jury or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe
practices which may result in minor personal injury or product
and property damage. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or operation.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury 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.
!WARNING
CUT HAZARD
Failure to follow this caution may result in personal injury.
When removing access panels 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 and wear
appropriate clothing, safety glasses, and gloves when handling
parts or reaching into the unit.
CAUTION
!
INTRODUCTION
The PHD4 heat pump is fully self−contained and designed for
outdoor installation. (See Fig. 1) Standard units are shipped in a
horizontal−discharge configuration for installation on a ground
level slab. Standard units can be converted to downflow (vertical)
discharge configurations for rooftop applications.
RECEIVING AND INSTALLATION
Step 1 — Check Equipment
Identify Unit
The unit model number and serial number are stamped on the
unit identification plate. Check this information against shipping
papers.
Inspect Shipment
Inspect for shipping damage before removing packaging
material. 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 distributor if any item is
missing. To prevent loss or damage, leave all parts in original
packages until installation.
Step 2 — Provide Unit Support
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 watertight 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) (See Fig. 8). This is
necessary for unit drain to function properly. Refer to accessory
roof curb installation instructions for additional information as
required.
Installation on older generation roof curbs.
Accessory kits are available to aid in installing a new “PHD4” unit
onto an existing roof curb designed for older generation units of a
similar design. 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.
CAUTION
!
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.

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518 01 2003 03
Slab Mount
Place the unit on a solid, level pad that is at least 2 in. (51 mm)
above grade (See Fig. 9). The pad should extend approximately
2 in. (51 mm) beyond the casing on all 4 sides of the unit. Do not
secure the unit to the pad except when required by local codes.
Step 3 — Provide Clearances
The required minimum service clearances are shown in Fig. 2
and 3. Adequate ventilation and outdoor air must be provided.
The outdoor fan draws air through the outdoor coil and
discharges it through the top fan grille. Be sure that the fan
discharge does not recirculate to the outdoor 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).
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.
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. Slab−mounted units
should be at least 2 in. (51 mm) above the highest expected
water and runoff levels. Do not use unit if it has been under
water.
Step 4 — Rig and Place Unit
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.
Inspection
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 injury or
death.
Never stand beneath rigged units or lift over people.
!WARNING
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.
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal
injury/death or property damage.
When straps are taut, the clevis should be a minimum of 36
in. (914 mm) above the unit top cover.
!WARNING

Fig. 2 −PHD424−30 Unit Dimensions
4518 01 2003 03

Fig. 3 −PHD436−60 Unit Dimensions
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518 01 2003 03

6518 01 2003 03
Fig. 4 −Roof Curb Dimensions
RETURN
AIR
SMALL
BASE
UNIT
SUPPLY
AIR
LARGE
BASE
UNIT
UNIT PLACEMENT ON
COMMON CURB
LARGE CURB SMALL OR LARGE BASE UNIT
SMALL/COMMON CURB
ROOF CURB DETAIL
Wood nailer*
(field supplied)
*Provided with roofcurb
Cant strip
field supplied
Roofing material
field supplied
Flashing field
supplied
HVAC unit
base rails
Roofcurb
Sealing
Gasket
HVAC unit
basepan
Anchor screw
C
B
AF
DE
Dashed lines show cross support
location for large basepan units.
G
H
C
B
A
F
D
E
G
H
field supplied
*
UNIT
SIZE
CATALOG
NUMBER
A
IN. (mm)
B (small/common
base)
IN. (mm)*
B (large base)
IN. (mm)*
C
IN. (mm)
D
IN. (mm)
E
IN. (mm)
F
IN. (mm)
G
IN. (mm)
H
IN. (mm)
Small or
Large
CPRFCURB010A00 11 (279) 10 (254)
14 (356) 16 (406) 47.8 (1214)
32.4 (822)
2.7 (69)
30.6 (778)
46.1 (1170)
CPRFCURB011A00 14 (356)
Large CPRFCURB012A00 11 (279) 14 (356) 43.9 (1116) 42.2 (1072)
CPRFCURB013A00 14 (356)
* Part Numbers CPRCURB010A00 and CPRCURB011A00 can be used on both small and large basepan units. The cross supports must be located based on whether the
unit is a small basepan or a large basepan.
NOTES:
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 mm) thick fiberglass 1 lb. density.

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518 01 2003 03
RIGGING WEIGHTS (SMALL CABINET) RIGGING WEIGHTS (LARGE CABINET)
Unit 24 30 Unit 36* 42* 48* 60*
lb kg lb kg lb kg lb kg lb kg lb kg
Rigging Weight 336 152 346 157 Rigging Weight 408 185 449 204 469 213 499 226
* For 460 volt units, add 14 lb (6.4 kg) to the weight.
NOTE: See dimensional drawing for corner weight distribution.
Rigging/Lifting of Unit (See Fig. 5)
Lifting holes are provided in base rails as shown.
1. 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).
2. 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 5 — Select and Install Ductwork
The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
non−residence type air conditioning and ventilating systems,
NFPA 90A or residence−type, NFPA 90B and/or local codes and
ordinances.
Select and size ductwork, supply−air registers, and return air
grilles according to ASHRAE (American Society of Heating,
Refrigeration, and Air Conditioning Engineers)
recommendations.
The unit has duct flanges on the supply−and return−air openings
on the side of the unit.
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal injury or
death.
For vertical supply and return units, tools or parts could drop
into ductwork Install a 90 degree turn in the return ductwork
between the unit and the conditioned space. If a 90 degree
elbow cannot be installed, then a grille of sufficient strength
and density should be installed to prevent objects from falling
into the conditioned space. Units with electric heaters require
90 degree elbow in supply duct.
!WARNING
When designing and installing ductwork, consider the following:
1. All units should 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.
2. Avoid abrupt duct size increases and reductions. Abrupt
change in duct size adversely affects air performance.
IMPORTANT: Use flexible connectors between ductwork and unit
to prevent transmission of vibration. Use suitable gaskets to
ensure weather tight and airtight seal. When electric heat is
installed, use fireproof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct.
ACCESS PANELS MUST BE IN PLACE WHEN RIGGING.
PANNEAUX D'ACCES DOIT ÊTRE EN PLACE POUR MANIPULATION.
50CY502286 2.0
CAUTION - NOTICE TO RIGGERS
PRUDENCE - AVIS AUX MANIPULATEUR
Use top skid as spreader bar. / Utiliser la palette du haut comme barre de répartition
SEAL STRIP MUST BE IN
PLACE BEFORE PLACING
UNIT ON ROOF CURB
DUCTS
DETAIL A
VOIR DÉTAIL A
MINIMUM HEIGHT: 36" (914.4 mm)
HAUTEUR MINIMUM
UNIT HEIGHT
HAUTEUR D'UNITÉ
SEE DETAIL A
VOIR DÉTAIL A
BANDE SCELLANT DOIT ÊTRE
EN PLACE AVANT DE PLACER
L'UNITÉ SUR LA BASE DE TOIT
Fig. 5 −Rigging Weights

8518 01 2003 03
Heat resistant duct connector (or sheet metal sleeve) must
extend 24−in. (610 mm) from electric heater element.
3. Size ductwork for cooling air quantity (cfm). The minimum
air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities
below those recommended.
4. Seal, insulate, and weatherproof all external ductwork.
Seal, insulate and cover with a vapor barrier all ductwork
passing through conditioned spaces. Follow latest Sheet
Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
Association (ACCA) minimum installation standards for
residential heating and air conditioning systems.
5. Secure all ducts to building structure. Flash, weatherproof,
and vibration−isolate duct openings in wall or roof
according to good construction practices.
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)
DISCHARGE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or
death.
Before performing service or maintenance operations on the
system, turn off main power to unit and install lockout tag.
!WARNING
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. 6.)
3. To remove downflow return and supply knockout covers,
break front and right side connecting tabs with a
screwdriver and hammer. Push cover down to break rear
and left side tabs.
NOTE: These panels are held in place with tabs similar to an
electrical knockout. Reinstall horizontal duct covers (Fig. 6)
shipped on unit from factory. Insure openings are air and
watertight.
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 side shot installation.
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.
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.
FIG. 6 −SUPPLY AND RETURN DUCT OPENINGS
Step 6 — Provide for Condensate Disposal
NOTE: Ensure that condensate−water disposal methods comply
with local codes, restrictions, and practices.
The units dispose of condensate through a 3/4 in. NPT female
fitting that exits on the compressor end of the unit. 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. 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 field−supplied 2 −in. (51mm) trap at the
condensate connection to ensure proper drainage. Condensate
trap is available as an accessory or is field−supplied. Make sure
that the outlet of the trap is at least 1 in. (25 mm) lower than the
unit drain−pan condensate connection to prevent the pan from
overflowing. Connect a drain tube using a minimum of
field−supplied 3/4−in. PVC or field−supplied 3/4−in. copper pipe
at outlet end of the 2−in. (51 mm) trap. (See Fig. 7) Do not
undersize the tube. Pitch the drain tube downward at a slope of
at least 1 in. (25 mm) every 10 ft (3 m) of horizontal run. Be sure
to check the drain trough for leaks. Prime the trap at the
beginning of the cooling season start−up.

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518 01 2003 03
TRAP
OUTLET
1-in. (25 mm) min.
2-in. (51 mm) min.
Fig. 7 −Condensate Trap
A
B
C
MAXIMUM ALLOWABLE
DIFFERENCE in. (mm)
A-C
1/4 1/4 1/4
(6.35) (6.35) (6.35)
A-B B-C
Fig. 8 −Unit Leveling Tolerances
FIG. 9 −SLAB MOUNTING DETAIL
OPTIONAL
RETURN
OPTIONAL
SUPPLY
EVAP. COIL COND. COIL
2”
50.8mm
Step 7 — Install Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury 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.
!WARNING
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. Do not damage internal components when drilling
through any panel to mount electrical hardware,
conduit, etc.
!CAUTION
High−Voltage Connections
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 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. Remove high voltage knockout.
See unit wiring label (Fig. 12−17) and Fig. 10 for reference when
making high voltage connections. Proceed as follows to
complete the high−voltage connections to the unit.
POWER
SUPPLY
FIELD-SUPPLIED
FUSED DISCONNECT
HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)
EQUIP GR
CONTROL BOX
LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL
)
W1
Y
G
R
C
WHT(W1)
YEL(Y)
GRN(G)
RED(R)
BRN(C)
THERMOSTAT
(TYPICAL)
ORN(O)
3-PHASE SHOWN
1-PHASE USES
TWO POWER
LEADS
W2
VIO (W2)
O
SPLICE BOX
DH
BLU(DH)
3-Phase
Only
GRA(Y2)
Fig. 10 −High−and Control−Voltage Connections
Single phase units:
1. Run the high−voltage (L1, L2) and ground lead into the
control box.

10 518 01 2003 03
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 L1 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 L1 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
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off
main power to system. 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 208. This retaps
transformer to primary voltage of 208 vac.
!WARNING
Control Voltage Connections
NOTE: 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.
Standard Connections
Locate the eight (nine 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 operation of unit. A gray wire is standard on
3−phase units for connection to an economizer.
If an accessory electric heater is installed, low voltage leads from
heater must be connected to factory supplied control leads from
Indoor Fan Board P4 connector.
NOTE: If the unit 24V wires do not have a matching receptacle,
cut the 24V wires from the electric heater plug, strip the ends,
and wire nut together to match the schematic connections. If the
electric heater 24V wires do not have a matching plug, cut the
24V wires from the unit receptacle, strip the ends, and wire nut
together to match the schematic connections.
Factory wires are provided for electric heat staging W1 and W2
(W2 and W3 on IFB). If room thermostat has only one stage of
supplemental heat, connect white and violet wires shown in Fig.
10 to second stage heat field wire.
Some electric heaters have four control wires (plus common
wire). Consult unit wiring diagram and electric heater wiring
diagram for additional details.
Transformer Protection
The transformer is of the energy−limiting type. It is set to
withstand a 30−second overload or shorted secondary condition.
If an overload or short is present, correct overload condition and
check for blown fuse on Interface Fan Board. Replace fuse as
required with correct size and rating.
Accessory Electric Heaters Installation
Electric heaters may be installed with the PHD4 units per
instructions supplied with electric heater package. See unit rating
plate for factory−approved electric heater kits.
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 airflow.
c. ELECTRIC HEATING MODE
(1.) Thermostat closes circuit R to W/W1, or W2 and R
to G. There are no on or off delays.
d. HEAT PUMP HEATING MODE
(1.) Thermostat closes circuits R to G and R to Y. The
compressor, indoor and outdoor fans are ener-
gized.
e. HEAT PUMP HEATING WITH AUXILIARY ELECTRIC
HEAT
(1.) Thermostat closes circuits R to G, R to Y and R to
W/W1 or W2. The compressor, indoor and outdoor
fans are energized, as well as the electric heat
relays.
f. DEFROST MODE
The defrost mode is automatically energized by the
defrost board during heating mode. The defrost board
energizes “O” (reversing valve) and “W2” (electric
heat). It also de−energizes the outdoor fan. When
defrost is complete, unit will return to heating mode. If
room thermostat is satisfied during defrost, unit will shut
down and restart in defrost on next call for heat.

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518 01 2003 03
Table 1 – Physical Data −Unit PHD4
UNIT SIZE 24 30 36 42 48 60
NOMINAL CAPACITY (ton) 2 2.5 3 3.5 4 5
Shipping Weight (lb)
(kg)
354
161
346
157
426
193
472
214
460
209
506
230
Compressor Quantity 1
Type Scroll
Refrigerant R410A
Refrigerant Quantity (lb)
Quantity (kg)
11.1
5.0
10.3
4.7
9.9
4.5
11.3
5.1
12.5
5.7
15.2
6.9
Refrigerant Metering Device Indoor TXV, Outdoor Dual Orifice
Orifice OD (in)
(mm)
0.032 (2)
0.81 (2)
0.037 (2)
0.94 (2)
0.038 (2)
0.97 (2)
0.040 (2)
1.02 (2)
0.040 (2)
1.02 (2)
0.049 (2)
1.24 (2)
Outdoor Coil
Rows...Fins/in,
face area (sq. ft.)
2...21
13.6
2...21
13.6
2...21
13.6
2...21
17.5
2...21
17.5
2...21
23.3
Outdoor Fan
Nominal Airflow (cfm)
Diameter (in.)
Diameter (mm)
Motor hp (rpm)
2500
24
610
1/10 (810)
2700
24
610
1/5 (810)
3100
26
660
1/5 (810)
3100
26
660
1/5 (810)
3100
26
660
1/5 (810)
3500
26
660
1/4 (810)
Indoor Coil
Rows...Fins/in,
face area (sq. ft.)
3...17
3.7
3...17
3.7
3...17
4.7
3...17
4.7
3...17
5.6
3...17
5.6
Indoor Blower
Nominal Airflow (cfm)
Size (in.)
Size (mm)
Motor hp (rpm)
800
10 x 10
254 x 254
1/2
1000
10 x 10
254 x 254
1/2
1200
11 x 10
279 x 254
3/4
1400
11 x 10
279 x 254
3/4
1600
11 x 10
279 x 254
1
1750
11 x 10
279 x 254
1
High Pressure Switch (psig)
Cutout
Reset (Auto)
650 +/ 15
420 +/ 25
LossofCharge/Low Pressure Switch (psig)
Cutout
Reset (Auto)
20 +/ 5
45 +/ 10
Return Air Filters
disposable (in)
(mm)
20x20x1
508x508x25
20x24x1
508x610x25
24x30x1
610x762x25
24x36x1
610x914x25
*Required filter sizes shown are based on the larger of the AHRI rated cooling airflow or the heating airflow velocity of 300 ft/minute for throwaway type or
450 ft/minute for high−capacity type. Air filter pressure drop for non−standard filters must not exceed 0.08 IN. W.C.
If using accessory filter rack refer to the filter rack installation instructions for correct filter size and quantity.
 For 460 volt units, add 14 lb (6.4 kg) to the weight.
Table 2 – Minimum Airflow for Reliable Electric Heater Operation (CFM)
SIZE PHD424 PHD430 PHD436 PHD442 PHD448 PHD460
AIRFLOW (CFM) 800 1025 1250 1400 1710 1800
INDOOR
THERMOSTAT
DISCONNECT
PER NEC
FROM
POWER
SOURCE
RETURN
AIR
TOP COVER
POWER ENTRY
CONTROL ENTRY
Fig. 11 −Typical Installation

12 518 01 2003 03
FIG. 12 −CONNECTION WIRING SCHEMATICS 208/230−1−60

13
518 01 2003 03
FIG. 13 −LADDER WIRING SCHEMATICS 208/230−1−60

14 518 01 2003 03
FIG. 14 −CONNECTION WIRING SCHEMATICS −208/230−3−60

15
518 01 2003 03
FIG. 15 −LADDER WIRING SCHEMATICS −208/230−3−60

16 518 01 2003 03
FIG. 16 −CONNECTION WIRING DIAGRAM 460−3−60
FIELD
SUPPLY
CF
SCHEMATIC
460−3−60
1
1
0
G
ENERGIZED
T
G
DE−ENERGIZED
0
W
45
BR
T
W
T+45
BR
ENERGIZED DE−ENERGIZED
T+90
HEATING FAN LOGIC
COOLING FAN LOGIC
EQUIP_GND
COMP
T1
T2
T3
OFM
CAP1
YEL
BRN
C
11 21
13 23
YEL
BLU
COMPRESSOR PLUG
BLU
BLK
BLK
CCH
GRN
NOTES:
1. IF ANY OF THE ORIGINAL WIRES FURNISHED ARE REPLACED,
THEY MUST BE REPLACED WITH THE SAME WIRE OR ITS EQUIVALENT.
2. SEE PRICE PAGES FOR THERMOSTATS.
3. USE 75 DEG. COPPER CONDUCTORS FOR FIELD INSTALLATION.
4. SEE INSTALLATION INSTRUCTIONS
FOR PROPER HEATING AND COOLING CONNECTIONS
FOR YOUR UNIT. INDOOR FAN MOTOR PLUGS
−DO NOT DISCONNECT UNDER LOAD
5. THESE FUSES ARE MANUFACTURED BY COOPER BUSSMANN,
P/N FNQ−R−5.
6. THIS FUSE IS MANUFACTURED BY LITTELFUSE, P/N 257003.
7. REMOVE YELLOW SPLICE WHEN ECONOMIZER AND ECONOMIZER
RELAYS ARE USED AND CONNECT TO RELAY R1 AS SHOWN.
8. WHEN ECONOMIZER AND ECONOMIZER RELAYS ARE USED,
CONNECT THE YELLOW AND BLACK WIRES TO RELAY RAS
SHOWN. RELAY KIT REQURED WITH ECONOMIZER AND HEAT
9. WHEN ECONOMIZER AND ECONOMIZER RELAYS ARE USED, INSTALL
WIRES AS SHOWN ONTO THE COILS OF RELAY R AND RELAY R1.
10.DEHUM FEATURE CANNOT BE USED WHEN ECONOMIZER IS INSTALLED.
UNIT FACTORY−SHIPPED IN STD MODE.
RED
BLK
BLK
YEL
DANGER: ELECTRICAL SHOCK HAZARD DISCONNECT POWER BEFORE SERVICING
YEL
RED
GRN
VIO
Y1
R
G
V
COLOR CODE
BLK BLACK
BLU BLUE
BRN BROWN
GRY GRAY
GRN GREEN
ORN ORANGE
PNK PINK
RED RED
VIO VIOLET
WHT WHITE
YEL YELLOW
BRNC
YEL
O
BLU
BLU
LPS
PNK
RVS
DFT
DIP SWITCH SETTINGS
30 MINUTES 60 MINUTES ON
90
DEFAULT
90 MINUTES
OR
OFF
SHIFT
(DEFAULT)
QUIET
OROR
60
FIELD SELECTABLE OPTIONS FOR TIME PERIOD
BETWEEN DEFROST CYCLES (MINUTES)
1) MOMENTARILY SHORT PINS AND RELEASE TO BYPASS
COMPRESSOR OFF DELAY.
2) SHORT FOR 5+ SEC. AND RELEASE FOR FORCED DEFROST.
3) PERMANENT SHORT WILL BE IGNORED.
DEFROST WILL TERMINATE IN 30 SEC. IF DFT OPEN.
DEFROST WILL TERMINATE NORMALLY IF DFT IS CLOSED.
THE COMPRESSOR WILL SHUT OFF FOR 30 SEC. ON DEFROST
INITIATION AND TERMINATION IN THE QUIET SHIFTON
POSITION
SPEED
UP
JUMPERED TEST PINS (USE METAL
OBJECT) FIELD SPEED−UP CYCLE
11 1
1133 333
22 2
22
30
60
30
120
90
UP
SPEED
P1 P3
P2
CTD
DEFROST BOARD (DB)
DR
OF2
OF1
0
W2
R
Y
DFT
T2
T1
O
R
Y
C
C
C
BLK BRN
BRN
PNK
IF USED
BLK BLK
OFR
13
WHT
ORN
BLK
RED
BLU
PNK ORN
RED
120 MINUTES
P4
P2
P1 R
C
COM
HIGH
3A
FUSE
Y
1
2
4
3
5
1
2
3
4
Y
R
W2
C
W2
W3
W3
C
W2
COM
24VAC
COM
5
4
3
2
1
6
7W3
W2
G
Y2/DH
Y1/Y
R
C
IFB
WHT
W
BRN
ACCESSORY ELECTRIC HEAT
HR1 (5 KW)
HR1 & 2 (10 KW)
HR1,2 & 3 (15 KW)
HR1,2,3 & 4 (20 KW)
HR3
HR2
HR4
HR1
BRN
BRN
BRN
BRN
BRN
1
1
1
1
1
WHT
VIO
PNK
GRY
BRN
WHT
VIO
PNK
GRY
BRN
BLU
WHT
VIO
PNK
GRY
BRN
COMP COMPRESSOR MOTOR
EQUIP EQUIPMENT
GND GROUND
IFM INDOOR FAN MOTOR
OFM OUTDOOR FAN MOTOR
TRAN TRANSFORMER
IFB INDOOR FAN BOARD
LPS LOW PRESSURE SWITCH
HPS HIGH PRESSURE SWITCH
T−STAT THERMOSTAT
DB DEFROST BOARD
DFT DEFROST TEMPERATURE
SWITCH
DR DEFROST RELAY
HR HEATER RELAY
RVS REVERSING VALVE
L1
L3
L2
OFR OUTDOOR FAN RELAY
LEGEND
FIELD SPLICE
TERMINAL (MARKED)
TERMINAL (UNMARKED)
SPLICE
SPLICE (MARKED)
FACTORY WIRING
FIELD CONTROL WIRING
FIELD POWER WIRING
ACCESSORY OR OPTIONAL
WIRING
C CONTACTOR
CAP 1 CAPACITOR, COMP
CCH CRANK CASE HEATER
AT AUTO TRANSFORMER
460V −230V
PRIMARY
460V
TRAN
SECONDARY
24V 24V24V
460
460
YEL
IFM
G
N
L
C
124 35
BRN
RED
BRN
GRN/YEL
BLK
FU1 5 AMP
FU2 5 AMP
RED
RED
BLK
BLK YEL
BLK
4
123
230V
460V
C
C
YEL
BLK
AUTOTRANSFORMER
BLK
RED
SEE NOTE 5
WHT
ORN
RED
BRN
OFR
BLU BRN
BLU
BLU
BLU
SEE NOTE 6
FU FUSE
R ECON RELAY
R1 ECON RELAY
7
6
11
10
8
2
3
4
1
5
9
12
BLK
BRN
RED
YEL
GRY
ECON PLUG
SAT
BLU
BLU
ECON
BLK
R
1
2
3
R1
1
2
3
YEL
YEL
BLK
GRY
Y2
T−STAT
YEL
RED
BRN
C
C1 C2
BRN
R1
C1 C2
R
C1 C2
SEE
NOTE 4
FOR WIRING WITH
ELECTRIC HEATERS
SEE SCHEMATIC
ON HEATER ACCESSORY.
DH DEHUMIDIFICATION MODE
DEHUM DEHUMIDIFICATION MODE
ECON ECONOMIZER
DEHUM
STD
BLUDH
STD STANDARD MODE
LOW
YEL
SEE
NOTE 7
SEE
NOTE 8
SEE NOTE 9
SEE NOTE 10
BLK
HPS
P
P
BLK BLK BLU BLU

17
518 01 2003 03
FIG. 17 −LADDER WIRING DIAGRAM 460−3−60
BLK
50EZ500354 E
DANGER: ELECTRICAL SHOCK HAZARD DISCONNECT POWER BEFORE SERVICING
YEL
C
21
L1
CCH
(IF USED)
C
11
13
COMP
CR
S
OFM
CAP
F
C
23
T3
T1
T2
BLK
YEL
YEL
YEL
BLK
RED BLK
L3
BLK
G/Y
BRN
USE COPPER CONDUCTORS ONLY
FIELD SUPPLY
460 VAC, 60 HZ, 3PH
GRN
11
TRAN
PRIMARY 460V
460V
24V
460V
24V
SECONDARY 24V
1
1
1
R
G
W
Y1
C
T’STAT
BLK YEL
BRN
24VAC R
FUSE
3A
P2−2Y
P1−1R
P1−4G
P1−6W2
P2−3W
P2−4R
P1−3Y1/Y
HIGH
12435
IFM
BLU
ORN
BRN
COM C
IFB−C
COM
IFB P1−2
IFB
11 13
WHT
RED
RED
PNK
RED
BLK
BLU
DB
PNK
PNK
DFT
LPS
BLU
YBLU
T1
BLU
T2
O
BLK BRN
RVS
P3−2
P3−1
C
BRN
P2−1
P2−4
P1−6,W2
P1−5,Y
P1−8,O
P1−7,R
1
OORN
WHT
BRN
ORN
Y
P2−1CBRN
DB−C
IFB
IFB
1
VP1−7W3
P1−2C
P1−4,C
BRN
RED
BLU
L2
OFR
13
OFR
OF2 BLU
OF1 BLU
IFB
24V SPLICE
DISCONNECT
PER NEC
EQUIP.
GND
OFM
CONTROL BOX AREA
COMP
C
S
R
CAP
HCF
IFM
UNIT COMPONENT ARRANGEMENT
OUTDOOR FAN
SECTION
COMPRESSOR
SECTION
INDOOR FAN
SECTION
TRAN
SINGLE PT.
CONNECTION
FOR
ELECT.HEAT
SEE HEATER
SCHEMATIC
FOR WIRING
24V POWER ENTRY
LPS
BOX
CCH
AT
SEE NOTE 6
RED
BLK
IFM
X
N
G
L
C
GRN/YEL
FU1 5 AMP FU2 5 AMP
BLK YEL
AUTOTRANSFORMER
PRIMARY 460V −SECONDARY 230V
BLK RED
SEE NOTE 5 SEE NOTE 5
C
21
23
13 11
FU1
FU2
OFR
4
2
3
7
5
6
8
Y2
GRY
RED
ECON
PLUG
IFB
COM
BLK
BRN
PNK BLU
PNK BLU
SAT
R
R1
R
1
2
3
R1
1
2
3
BLK
YEL
YEL
BLK
YEL
BRN
YEL
C
C
CAP 1
CF
DB
RR1
DH P1−5Y2/DH
RED
GRN
WHT
YEL
BRN
VIO
BLU
LOW
SEE NOTE 4
SEE NOTE 8
YEL
SEE NOTE 7
DEHUM
STD
SEE
NOTE 10
SEE NOTE 9
HPS
HPS
P4−5W3
GRY
P4−4W3
PNK
P4−3W2
VIO
P4−2W2
WHT
P4−1C
BRN
TO ACCY
HEATER
GRY
YEL
BLU BLK
BLK

18 518 01 2003 03
PRE−START−UP
FIRE, EXPLOSION, ELECTRICAL AND
ENVIRONMENTAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Relieve and recover all refrigerant from system before
touching or disturbing compressor plug if refrigerant leak
is suspected around compressor terminals.
3. Do not remove compressor plug until all electrical sources
are disconnected and tagged.
4. Never attempt to repair soldered connection while
refrigerant system is under pressure.
5. 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.
!WARNING
Use the Start−Up Checklist supplied at the end of this book and
proceed as follows to inspect and prepare the unit for initial
start−up:
1. Remove all access panels.
2. Read and follow instructions on all DANGER, 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. Leak−test all refrigerant tubing
connections using electronic leak detector, or
liquid−soap solution. If a refrigerant leak is detected,
see following Check for Refrigerant Leaks section.
c. Inspect all field and factory−wiring connections. Be
sure that connections are completed and tight. Ensure
wires do not touch refrigerant tubing or sharp sheet
metal edges.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that outdoor−fan blade is correctly
positioned in fan orifice.
b. Make sure that air filter(s) is in place.
c. Make sure that condensate drain pan and trap are
filled with water to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose parts
have been removed.
5. Each unit system has 2 Schrader−type ports, one
low−side Schrader fitting located on the suction line, and
one high−side Schrader fitting located on the compressor
discharge line. Be sure that caps on the ports are tight.
START−UP
Checking Cooling and Heating Control Operation
Start and check the unit for proper control operation as follows:
(1.) Place room thermostat SYSTEM switch or MODE
control in OFF position. Observe that blower motor
starts when FAN mode is placed in FAN ON
position and shuts down when FAN MODE switch
is placed in AUTO position.
(2.) Thermostat:
When the room temperature rises to a point that is
slightly above the cooling control setting of the
thermostat, the thermostat completes the circuit
between thermostat terminal R to terminals Y, O
and G.These completed circuits through the
thermostat connect contactor coil (C) (through unit
wire Y) and Indoor Fan board (through unit wire G)
across the 24−v. secondary of transformer (TRAN).
(3.) Place system switch or MODE control in HEAT
position. Set control above room temperature.
Observe that compressor, outdoor fan, and indoor
blower motors start. Observe that heating cycle
shuts down when control setting is satisfied.
(4.) When using an automatic changeover room
thermostat place both SYSTEM or MODE control
and FAN mode switches in AUTO positions.
Observe that unit operates in Cooling mode when
temperature control is set to “call for Cooling”
(below room temperature), and unit operates in
Heating mode when temperature control is set to
“call for Heating” (above room temperature).
NOTE: Once the compressor has started and then has stopped,
it should not be started again until 5 minutes have elapsed. The
defrost board has a built−in 5 minute delay between cycles. The
5 minute compressor delay also applies to heat pump heating
mode.
Step 1 — 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 R−410A refrigerant, using an electronic
scale. Refer to unit rating plate for required charge.
Step 2 — Start−Up Adjustments
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 unit in Cooling mode
when the outdoor temperature is below 40F (4C) (unless
accessory low−ambient kit is installed).
IMPORTANT: Three−phase, scroll compressors 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 may be near zero.

19
518 01 2003 03
Checking and Adjusting Refrigerant Charge
The refrigerant system is fully charged with R−410A refrigerant
and is tested and factory sealed.
NOTE: Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R−410A
charge.
A subcooling charging chart is attached to the inside of the
compressor access panel. 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.
NOTE: Allow system to operate for a minimum of 15 minutes
before checking or adjusting refrigerant charge.
IMPORTANT: 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. Using hoses with valve core depressors, attach low−and
high−pressure gauge hoses to low−and high−pressure
service fittings, respectively.
3. Start unit and let 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]) at TXV.
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. 19).
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 Check for Refrigerant Leaks section.
Airflow Adjustments
UNIT 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.
CAUTION
!
NOTE: Be sure that all supply−and return−air grilles are open,
free from obstructions, and adjusted properly.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect electrical power to the unit and install
lockout tag before changing blower speed.
!WARNING
This unit is factory-set up for use with a single cooling fan speed.
In addition, this unit has the field-selectable capability to run two
different cooling fan speeds: The rated cooling fan speed
(350~400 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.
The cooling speed is marked “LOW” on the interface fan board
(IFB) (Fig. 18) . The factory-shipped settings are noted in Table
4. There are 4 additional speed tap wires available for use in
either electric heating or cooling (For color coding on the indoor
fan motor leads, see Table 3). The additional 4 speed tap wires
are shipped loose with vinyl caps and are located in the control
box, near the interface fan board (IFB) (Fig. 18).
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 3 for color coding). Add the wet coil
pressure drop in Table 5 to the system static to determine
the correct cooling airflow speed in Table 4 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. 18) 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).
NOTE: If accessory electric heat is installed, and the electric
heat fan speed is chosen to be the same as the normal cooling
fan speed, the dry airflow must meet or exceed the minimum
airflow speed specified in Table 2 for the specific size unit.
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. Using Fig. 18, move the two pin DEHUM jumper from the
“STD” position to the “DEHUM” position.
2. Remove fan speed tap wire from the “LOW” terminal on
the interface fan board (IFB) (Fig. 18).
3. Determine correct normal cooling fan speed for unit and
application. Add the wet coil pressure drop in Table 5 to
the system static to determine the correct cooling airflow
speed in Table 4 that will deliver the nominal cooling
airflow as listed in Table 1 for each size.
NOTE: If accessory electric heat is installed, the dry
airflow must meet or exceed the minimum airflow speed
specified in Table 2 for the specific size unit. The electric
heat fan speed will be the same as the normal cooling fan
speed.

20 518 01 2003 03
4. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 3 for color coding) for the normal cooling
fan speed and place desired speed tap wire on “HIGH” on
the interface board.
5. Refer to airflow tables (Table 4) to determine allowable
speeds for the dehumidification cooling fan speed. In
Table 4, speeds that are not allowed for dehumidification
cooling are shaded.
6. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 3 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.
7. Use any spare vinyl plugs to cap any unused speed tap
wires.
Single Speed Cooling With Higher Electric Heat
Speed
This unit can also be configured to operate with single speed
cooling and a higher speed for an accessory electric heater.
1. Move the two pin DEHUM jumper located on control board
(see Fig. 18) from the “STD” position to the “DEHUM” posi-
tion.
2. See Table 2 for minimum airflow for electric heat operation.
Add electric heater and filter pressure drop to duct system
static pressure to determine total external static pressure.
3. Select speed tap from Table 4 that will achieve required
airflow from Table 2.
4. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 3 for color coding).
5. Connect the desired speed tap wire to the “HIGH” terminal
on the interface fan board (IFB).
UNIT OPERATION HAZARD
Failure to follow this caution may result in unit
component damage or improper operation.
To use this mode, a speed connection must be made
on the “HIGH” terminal that meets or exceeds the
minimum airflow found in Table 2.
!CAUTION
Table 3 – Color Coding for Indoor Fan Motor Leads
Black = High Speed
Orange = Med−High Speed
Red = Med Speed
Pink = Med−Low Speed
Blue = Low Speed
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect electrical power to the unit and install
lockout tag before changing blower speed.
!WARNING
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 Figure 18).
HIGH LOW COM
QC5 QC4 QC3
KZ KL
07 09 080L0 ALO R13 C8 R11 Q1
Q3
D2
AL2
DCR QCR
QC1
C
RL
01
G1
G2
Z1
A7 R9 AB A15
C4
C9
C0
QIL Z2 06 04
U1
C3 R4 RL4
JWZ
C7
D5 D3
R3 R5 R6
R2 JW5
QCB
YR W2 Y C W3W3W2 W2C
JW4
P2 JW3
P4
P1
W2W3 Y2 Y1
YDH GCR
SSTZ-8
P3 SDL
24VAC/R3AMP CDM/C
F1
STD DEHUM
Fig. 18 −Interface Fan Board (IFB)