Carrier COMFORT 50EZ-A User manual

Installation Instructions
to the expe_
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 ....................... 1-2
INTRODUCTION ................................... 2
RECEIVING AND INSTALLATION .................. 2-9
Check Equipment .................................. 2
Identify Unit .................................... 2
Inspect Shipment ................................. 2
Provide Unit Support ............................... 2
Roof Curb ...................................... 2
Slab Mount ..................................... 2
Provide Clearances ................................. 2
Rig and Place Unit ................................. 3
Inspection ...................................... 3
Rigging/Lifting of Unit ............................ 7
Select and Install Ductwork ........................... 7
Converting Horizontal Discharge Units to Downflow
(Vertical) Discharge Units .......................... 8
Provide for Condensate Disposal ...................... 9
Install Electrical Connections ......................... 9
High-Voltage Connections ......................... 9
Special Procedures for 208-V Operation .............. 10
Control Voltage Connections ....................... 10
Standard Connections ............................ 10
Transformer Protection ........................... 10
Accessory Electric heaters Installation ................ 10
PRE-START-UP ................................... 18
START-UP ..................................... 18-24
Checking Cooling & Heating Control Operation ........ 18
Check for Refrigerant Leaks ......................... 18
Start-Up Adjustments ............................. 18
50EZ-A Sequence of Operation .................... 19
Checking & Adjusting Refrigerant Charge ............ 19
Indoor Airflow & Airflow Adjustments .............. 19
Continuous Fan Operation ........................ 20
Defrost Control ................................... 24
Quiet Shift ..................................... 24
Defrost ....................................... 24
MAINTENANCE .................................. 24-
Air Filter ........................................ 24
Indoor Blower and Motor ........................... 24
Outdoor Coil, Indoor Coil, & Condensate Drain Pan ...... 25
Outdoor Fan ..................................... 25
Electrical Controls and Wiring ....................... 27
Refrigerant Circuit ................................. 27
Indoor Airflow ................................... 28
Metering Devices- TXV & Piston .................... 28
Pressure Switches ................................. 28
Loss of Charge Switch ............................. 28
High Pressure Switch .............................. 28
Copeland Scroll compressor (Puron Refrigerant) ......... 28
A09034
Fig. 1 - Unit 50EZ-A
Refrigerant System ................................ 28
Refrigerant .................................... 28
Compressor Oil ................................. 28
Servicing Systems on Roofs with Synthetic Materials .... 28
Liquid Line Filter Drier ........................... 29
Puron® (R-410A) Refrigerant Charging ............. 29
System Information ................................ 29
Loss of Charge Switch ............................ 29
Check Defrost Thermostat ......................... 29
TROUBLESHOOTING .............................. 29
START-UP CHECKLIST ............................ 29
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 Z_.
When you see this symbol on the unit and in instructions or manu-
als, be alert to the potential for personal iniury. 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 iniury

ordeath.WARNINGsignifieshazardswhichcould 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
injury or death.
Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be
more than one disconnect switch. Turn off accessory heater
power switch if applicable.
FIRE, EXPLOSION, ELECTRICAL SHOCK
HAZARD
Failure to follow this warning could result in personal
injury, 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 injury.
When removing access panels (see Fig. 20) 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 50EZ-A 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
groundlevel 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 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 distributor 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 5to 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.
IMPORTANT: The unit must be secured to the curb by installing
screws through the bottom of the curb flange and into the unit base
rails. When installing large base units onto the common curb, the
screws must be installed before allowing the full weight of the unit
to rest on the curb. A minimum of six screws are required for large
base units. Failure to secure unit properly could result in an
unstable unit. See Warning near Rigging/Lifting information and
accessory curb instructions for more details.
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. 6). 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 a new "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 personal injury.
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 (See Fig. 8).
The slab should extend approximately 2 in. (51 mm) beyond the
casing on all 4 sides of the unit. Do not secure the unit to the slab
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 4 in. (102 ram) 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
nmst 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
injury/death or property damage.
When straps are taut, the clevis should be a nfinimum of 36 in.
(914 ram) above the unit top cover.

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50EZ A24 30
50EZ A_O [5/5)0
_OEZ _36 {3/5)0
_OEZ _5_ 60
ELECTRICAL UNIT WT UNIT HEIGHT INMI4 CEI_TER OF GRAVIT_ INM_
CHARACTERISTICS LB K6 "_" X ,'
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OPTIOUS EXCEPT EGO_40NIZER REQUIR_ CLEARANCESTO COI_BUSTIBLEMATL. IsCHES [Nb]
TO? OF UNIT............................... _ [305 6]
OUCT SIDE OF UNIT 2 [50 8]
S[OE ORPOS[TE DUCTS .......................... 14 [355 6]
BOTTOI_OF UNIT ................. 0 [00]
ELEI;TRIE-'LPANEL 36 [9i4 4]
NEE. REQUIRED CLEARANCES• I 4CHES [r_4]
BET_'EEI' U ITS PO_'ER EsTRY SlOE 12 [i066 8]
UNIT A[i [4GiOLN E') SURF_ ES PO',_ER ENTR' SIEE ..... 36 [914 O]
d_IT AI40 BLOCK OR 0% ETE WALLS AND OTHER
_,I<OUs)E) L FAES P,X%E Er, TRT I[E 4;' [106 8]
REQUIRB_) CLEARANCE FOR OPERATION AND SER'_IClN6 I'_OH ES [M_4]
E_'d _ OIL AC ESS SI E ........ 56 [ 40]
/',}WE EtqTR SI}E 42 [/0668]
,EXCEPT FOR HEO [EOUIIE_!EHTS)
IIIT TOP ,18 [1 19 ]
SIDE OPPOSITE DOTS .......................... 56 [9 40]
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NEC.REQUIREDCLEARANCES.
Ur,IT A'\D BLOCFOR CO%CRETEt,ALLS A'4D OTHER
GRObME; SUGFACES PO,&ERE_TRY S[E 48 [0668]
REQUIREDCLEARANCEFOR OPERATIONANDSERVICING
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(EXCE-T FOR qEC EQUIREI,_ESTS
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CT PA_,EL........................ 12 [3048]_
LEFT SIDEVIEW FRONT VIEW RIGHT SIDE VIEW REAR VIEW

F A
ROOF CURB DETAIL
LARGE CURB
/
A09415
t
A
Dashed I_nes shaw crass support
location for large basepan units
SMALL/COMMON CURB A09413
SMALL
BASE
UNIT
LARGE
BASE
UNIT
-a
UNIT PLACEMENT ON
COMMON CURB
SMALL OR LARGE BASE UNIT
A09094
A09414
B
UNIT CATALOG A(small/common
SIZE NUMBER IN. (mm) base)
IN. (mm)*
Small CPRFCURB010A00 11 (279)
or 10 (254)
Large CPRFCURB011A00 14 (356)
CPRFCURB012A00 11 (279)
Large 14 (356)
CPRFCURB013A00 14 (356)
BCD E F G H
(large base)
IN. (mm)* IN. (mm) IN. (mm) IN. (mm) IN. (mm) IN. (mm) IN. (mm)
32.4
47.8 (822) 30.6 (778) 46.1
14 (356) 16 (406) (1214) 2.7 (69) (1170)
43.9 42.2 (1072)
(1116)
* 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 1d-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.
Fig. 4 - Roof Curb Dimensions

CAUTION - NOTICE TO RIGGERS
PRUDENCE - AViS AUX MANIPULATEUR
ACCESS PANELS MUST BE iN PLACE WHEN RIGGING.
PANNEAUX D'ACCES DOlT i_TRE EN PLACE POUR MANIPULATION.
Use top skid as spreader bar. /Utiliser la palette du haut comme barre de repartition
jJ ..... MiNiMUM HEIGHT: 36" (9!4.4 ram)
JHAUTEUR MINIMUM
DUCTS
SEE DETAIL A
VOIR DETAIL A J
UNIT HEIGHT
HAUTEUR D'UNITEJ"
DETAIL A
VOIR DIETAIL A
SEAL STRIP MUST BE IN BANDE SCELLANT BOIT ETRE
PLACE BEFORE PLACING EN PLACE AVANT DE PLACER
UNIT ON ROOF CURB L:U NtTE SUR LA BASE DE TOtT
50CY502286 2,0
CORNER WEIGHTS (SMALL CABINET)
24 30
Unit Ib kg Ib kg Ib
Rigging 327 148 340 154 343
Weight
*For 460 Volt units add 14 Ib (6.35 kg) to the rigging weight.
NOTE: See dimensional drawing for corner weights.
36 Unit
kg
156 Rigging
Weight
Fig. 5 -Rigging Weights
CORNER WEIGHTS (LARGE CABINET)
42 48
Ib kg Ib kg
419 190 429 195
Ib
454
Riuuinu/Liftinu of Unit (See Fiu. 5.)
6O
A09051
kg
2O6
UNIT FALLING HAZARD
Failure to follow this warning could result in personal iniury
or death.
Large base units must be secured to common curb before
allowing full weight of unit to rest on curb. Install screws
through curb into unit base rails while rigging crane is still
supporting unit.
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).
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.
B
A-B
1/4 (6.35)
MAXIMUM ALLOWABLE
DIFFERENCE in. (mm)
B-C A-C
1/4 (6.35) 1/4 (6.35)
A07925
Fig. 6-Unit Leveling Tolerances
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
iniury 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.
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. 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.
Converting Horizontal Discharge Units to Downflow
(Vertical) Discharge Units
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 and install lockout tag. There may be more
than one disconnect switch.
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. 70
Horizontal Duct Covers
A09061
Basepan
Downflow
(Vertical)
Supply Basepan
Downflow
Return
Knockout
A09088
Fig. 7 - Supply and Return Duct Openings
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.
3. To remove downflow return and supply knockout covers,
break front and right side connections 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. 7)
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 non
residence-type air conditioning and ventilating systems, NFPA
90A or residence-type, NFPA 90B; and/or local codes and
ordinances.
I
2" I
(50.8ram) I
±,,
IIIII IIII
_h
EVAR COIL COND. COIL
Fig. 8 -Slab Mounting Detail
A07926

Step 6-- Provide for Condensate Disposal
NOTE: Ensure that condensate-water disposal methods comply
with local codes, restrictions, and practices.
The 50EZ-A 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 @ron in ground
level installations. Install a field-supplied 2-in. (51 mm)
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 @ron, 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 tr@
is available as an accessory or is field-supplied. Make sure that the
outlet of the tr@ is at least 1 in. (25 mm) lower than the unit
drain-pan condensate connection to prevent the pan from
overflowing. Connect a drain trough 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) tr@. (See Fig. 10) Do not
undersize the tube. Pitch the drain trough 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.
Step 7 -- Install Electrical Connections
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.
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.
Hi,h-Voltage Connections
The unit must have aseparate 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. 11-13) and Fig. 9 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.
HIGH VOLTAGE !
POWER LEADS do-
(SEE UNIT WIRING|
LABEL) _:_
3-PHASE SHOWN
1-PHASE USES L._
TWO POWER
LEADS EQUIP GR
CONTROL BOX
LOW-VOLTAGE
POWER LEADS
(SEE UNIT) ......................
WiRiNG LABEL
SPLICE BOX
€O
O
0
O
O
O"
C-
O
O
FIELD-SUPPLIED
FUSED DISCONNECT
CHT.(Wb 'D-
t°(w2-)
LE L(Y-)-_.
GRN(-G2D-
R E.D_R_.{)_
BR_N(_C)_D_
D_RN_LOL_
_U(DH_)D_
LR_A_p
m
-@
-@
<S
-@
-@
©
©
.@
3-Phas6
Only
Fig. 9-High- and Control-Voltage Connections
THERMOSTAT
(TYPICAL)
A09071
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 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
injury or death.
Before installing or servicing system, always turn off main
power to system and install lockout tag. With disconnect
switch open, move black wire from transformer (3/16 in.)
terminal marked 230 to terminal marked 200. This retaps
transformer to primary voltage of 208 vac.
Control Voltage Connections
NOTE: Do not use any type of power-stealing thermostat, rkJnit
control problems may result.
Use no. 18 American Wire Gage (AWG) color-coded, insulated
5 °
(3. 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. 9 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. Factory wires are provided for
electric heat staging WI 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. 9 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 blower 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 50EZ-A units per
instructions supplied with electric heater package. See unit rating
plate for factory-approved electric heater kits.
l-in. (25 ram) rain.
TRAP
t
__1 )min.......
A09052
Fig. 10 - Condensate Trap
10