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

Table 1 - Physical Data - Unit 50EZ-A
50EZ-A30 50EZ-A36 50EZ-A42
2.8 3 3.8
340 343 419
154 156 190
1
SCROLL COMPRESSOR
R-410A
8.3 10.2 7.9 10.0
3.8 4.6 3.6 4.5
TXV
ORIFICE OD (in.)
(mm)
OUTDOOR COIL
Rows... Fins/in.
face area (sq. ft.)
OUTDOOR FAN
Nominal Airflow (CFM)
Diameter Motor HP (RPM)
INDOOR COIL
Rows... Fins/in.
face area (sq. ft.)
INDOOR BLOWER
Nominal Cooling Airflow (CFM)
Size (in.)
(me)
Motor (HP)
HIGH-PRESSURE SWITCH (psig)
Cutout
Reset (Auto)
LOSS-OF-CHARGE/LOW-PRESSURE
SWITCH
(Liquid Line) (psig)
Cutout
Reset (Auto)
RETURN-AIR FILTERS*l-
throwaway (in.)
(mm)
UNIT SIZE 50EZ-A24 50EZ-A48 50EZ-A60
NOMINAL CAPACITY (ton) 2 4 5
SHIPPING WEIGHTS (Ib) 327 429 454
(kg) 148 195 206
COMPRESSOR QUANTITY
TYPE
REFRIGERANT
Refrigerant (R-410A) Quantity (Ib) 9.6 12.3
Quantity (kg) 4.4 5.8
METERING DEVICE ID
0.038 (Left OD Coil)
0.032 (2) 0.035 (2) 0.037 (2) 0.040 (Right OD Coil) 0.046 (2) 0.052 (2)
.81 .89 .94 .97/1.02 1.2 1.3
2...21 2...21 2...21 2...21 2...21 2...21
11.9 11.9 11.9 13.6 13.6 17.5
2000 2700 2700 3100 3100 3500
24 24 24 26 26 26
1/5 (810) 1/5 (810) 1/5 (810) 1/5 (810) 1/5 (810) 1/5 (810)
3...17 3...17 3...17 3...17 3...17 3...17
3.7 3.7 3.7 4.7 4.7 5.7
800 1000 1200 1400 1600 1800
10x10 10x10 11x10 11x10 11x10 11x10
254x254 254x254 279x254 279x254 279x254 279x254
1/2 1/2 3/4 3/4 1.0 1.0
650-+15
420-+25
20-+5
45-+10
20-+5
45-+10
20x20x1 20x24x1 24x30x1 24x36x1
508x508x25 508x610x25 610x762x25 610x914x25
*Required filter sizes shown are based on the larger of the AHRI (Air Conditioning Heating and Refrigeration Institute) rated cooling airflow or the heating airflow
velocity of 300 ft/minute for throwaway type or 450 if/minute for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 IN.
W.C.
1-If using accessory filter rack refer to the filter rack installation instructions for correct filter size and quantity.
S For 460 volt units, add 14 Ib (6.4 kg) to the weight.
Table 2- Minimum Airflow for Reliable Electric Heater Operation (CFM)
SIZE 50EZ-A24 50EZ-A30 50EZ-A36 50EZ-A42 50EZ-A48 50EZ-A60
AIRFLOW (CFM) 800 1025 1250 1400 1710 1800
11

k v
J"' \ _""E ' ELECT? £<< L 8 H0'<:I":,,
F_OTES:
I IF ANY OF THE O{IGENAL ,','IRESF RNISHE¢ AIE
REPLACE_, THEY MdST BE REPLACE_) WITH THE
SAME WIRE OR IT8 E_UI,,ALENT
? SEE PRICE PAGES FOR THERMOSTATS¸
3 iiSE Y5 _E_ COPPER EONbiiCTO_S FOR FIELb
INSTALLATION
4 SEE ]NSTALLATIOR IRSTi_UCTIONS
FOR RROREF HEATING A_i)COOLING CONNECTIONS
FOR YOUR UN]T [NtOOR FAN MOTOR PLUGS
"90 NOT DISCONNECT JStER LOAf"
5, CCH NOT iiSE9 ON ALL UNITS,
6 THIS FUSE IS MA_SFAgT_REt _Y LITTELF_gE,
i _ _NIT FACTOR'_ SHIPPED IN STY)_OOE
J LEGE!ii}
j £iA FIELb SPLICE COMP COMPRESSOR MOTOI/
_)B tEFROST _OARi)
F[ELO /_ LF
{ CHE,,,,:_,:,TI ,<:
IF USE}_ CCH 9 "_ A 9 " M" f" ,q
LK
}BLK BLK_iPi_GF£LK,), ................... /"_, ¢OLOA O)E
P_BLKCBLK¢*LK .........
_LK, BLK LACK
GNY ONA'
'11 .........
EQ}[P G } OR_, OR_ (}E
L ',_16 ',_IOLET
._ CO!P 'tiHT ¢IHITE
O_>',#ESS} ILG ............
I!
COOLING FAN LOGIC
! T%0
ESE_GZZEStE ESE_¢IZEt
HEATING FAN LOGIC
_R
ENEi_GIZEt _E ENERGIZED
3PEE{)_ JW, E E) TEST >INS '{USE !,gET:L
OB EST} FIEL} SPEE} 8P ¢'CLE
i} MOMENTARILY SHORT PINS AND RELEASE TO _YPA88
COMI_I_ESS(}_ OFF 9ELAY,
_} SHORT FO_ _+ SEC, AN9 i_ELEA_E FO_ FO_CEO tEFi_OST,
3} PERMANENT SHORT _]LL BE IGNOREt,
i)EFROST WILL TE_ IRATE IX 30 SEC IF tFT OPEN
i)EFROST A"ILL TERSII!iS,TE iORALLY IF OFT IS ¢LOSEi}
THE ¢O!,PFESSOP /_i[LL ,_HT OFF FOR :_0 SE¢ ON )ED, OST
INITIATION ANt TER_,!]_ATIO_i I!i THE "Qii[ET SHIFT" O_
POSITION
Fig. 11 -Connection Wiring Schematics 208/230-1-60
A10197
12

BLK ;5E CO: _E:_' C0iD;CTO_S ONLF
FZELD SJ :>LF
08i?kO ""£" 60 H) ?H
I
G/'
BLII 'Eb
( IF,,, ,: ,S,"
X
_si_£,!._iY _08, ;SO'z/
BLK r'_ ........ s 'EL
L
EL
23
23
TO sCC"
HEATEi_
WHT%(1) i:'4 2 "'Ai2"
',,,'IOn()' 3"W "
? ',,,'A(' i/
5P;
YEL
WHT
RED
, i
...... SEE *,OTE 2
)x_oo r,
aECEO_4
_ETIO IECT]O_4
_E)
J,liH_
'E_
8Us
;;s C:
,. _,h
:"3 2\s
OP: 5.0
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EL[_TtE_T
__SEE HEaTEa
h_p'm
.ECU:P
9_e
Fig. 11 Cont. - Ladder Wiring Schematics 208/230-1-60
A10197
13

I!
¢@4_RESSOa
SECTIO_
ENERGIZE9 _E ENERGIZE9
SECTIO CONT_OLBOXA_EA
SI_GLE_ _
FO_
ELEC HE_T _
_ r_ _ _E_ _T_ _
{)IP SiIl'tIIiI T(: H SETTING
i)EFAULT
30 MINUTES 68 _]_UTES 90 _I_OTE$ i_0 _4INgTES
+
FIELD SELECTDBLE OPTIOn, S FOR TIME 8ERIOO
5ETWEEN i}EFROST CYCLES H,!INUTES}
S_'LE _ .;b_,*E/E} TEST >INS E !,ET_'L
'_" _ 0 ECT) FIEL} $ EED FIYCLE
i) _OMENTARILY SHORT7INS A@ RELEASE TO BYPASS
¢OMPiiESSOFiOFF 8ELAY
2} SHORT FOi7 S+ SEC AND RELEASE FOR FORCED DEFROST
3) PERMANENTSHORT WILL 8E IGNORED
_)EFisOSTWILL TEiW,!I _STEI 30 SE¢ IF {)FT O_-E,I
}EF_OST WILL TE_,I ATE Oi4ALL' IF )FT IS CLOSE)
THE ()OM:>_ESSO:/ _ilLL SH T OFF FOR 3,0 SE¢ ()5)EF%ST
INITI:_TIO :_ ) TE_,I 4TIO IN THE "Q;:IET SHIFT" 0
OSITIO
A10194
Fig. 12 -Connection Wiring Schematics -208/230-3-60
14

LK
](
1
ii
I
SE (IC,;_:SE._(ION}UCTO?3 ONLv (iv
FIEL) 8P_L '
208/8{S0 ',iA,C. 60 Hf, {_:H
_(s-- Lv,_,_ LK_ ,_" _SLv,_ 0 ..............
..............)_...... /'d?,\,_,,s_,_
;-_ LK(,!;!;q/I:,,iF£}4"LK_ LK_ LK_(. _:_,EL_/,,E L
I'EL//w I
.!, ..............
.... \cA _) ...................
LJ
L ...................
/'T_\
(T T4_'E
BLK 'EL ..............................
2}0 T:._ CO'
.:RI_,1.__Y 08i 30,i/ _
L F, 'EL
L5 I L2
,EL LU
i}
TO _ '_ ;" Y
HEI_TE _
IF
T'iTAT 'vAf i#
/\ /
FSE
/, ....
/..............
\_) 0/ii
Z
/\-I,.J
_ _ u_÷(>_ ,..._......,,
I
W III/_'H ) } 6 Ih'_'2 II I
,j
,- \j
}?11y 11/'_
',} -)''2 "_ II W II{?
2 ......s _/"
LO¢ (}
HI(HO
i
R_ /'} _> 4 1 IlCll
WHT_() p4 2IIW2II
,/ q
I,, /511W2II
I P_j_" " ;,> IlW } II
L 0,,, o,.,ilW ll
"_ SEE ,OTE 5
2_2Z
i
_,R,,s O-
i E) () i, :i
,SiHT OF _,_I
'tEL O:' )1 '(
OFO
OF0
T2
,,?_ (>
0
"(7
OFT
K
HPS
c
{{,/3
_.., IF_
•Js, !
c
IF C
{)B C
IFB
C0,I
IFB :_I 2
IF8
)C0_4 C
I!
Fig. 12 Cont. -Ladder Wiring Schematics -208/230-3-60
A10194
15

g
CONNECTION WIRING DIAGRAM
DANGER ELECTRICAL SHOCK HAZARD DISCONNECT POWERBEFORE SERVICING
,OTES: SCHEMATfC
1, IF ANYOF THE ORIGINAL WIRES FURNISHED ARE REPLACED,
THEY MUSTBE REPLACEDWITH THE DAMEWIRE OR ITS EQUIVALENT. IF USED_..
,. DEEPRICEPNOEDFORT,ERMOSTNTS. _ OO" 460 - 3 - 60
u,USEYsDEG.DO,PERCOBDUCTQRDFORFI,LD,BSTRLLATIOB, LRR!
4. SEE INSTALLATION INSTRUCTIONS
FOR PROPERBEATING AND COOLING CONNECTIONS D OFR OFM
FOR YOURUNIT, INDOOR FAN MOTORPLUGS fiLE
- 'DO NOT DISCONNECTUNDER LOAD' 7LK_C_L
5, THESEFUSES ARE MANUFADTUEEDBY COOPERBUGSMNBB, FIELD L1 /'_ I\ c co,oRcooE
PiN FNO-R-5. 1 I_"lV" 1 T'wI _L_ _E_ I
U, THIS FUSE IS MANUFACTUREDBY LETTELFUSE. PIN 25700U, ._ _ -_., M== _ Ill r_/_E'_lcAP1 N IIBLI BLACK
7, REMOVEYELLOWSPLICE WHEN ECONOMIZERAND ECONOMIZER SUPPLY L5 _t_.. __ -- _ c-I_l_:" ' \ I/0.. ...r
RELAYS ARE USED AND CONNECTTO RELAY R1 AS S_N. -- -- "_ L_YEL I_ _ I_eR_ _ _X_,,
8, WHENECONOMIZERAND ECONOMIZERRELAYSARE USED, L2 _I_I I_; r -- ''' um' u"v""
CONNECTTHE YELLOWAND BLACKWIRES TO RELAY "R' AS -- -- _L--I __L GRY GRAY
sHowB.RELN,KITRE+RED,IT,ECOUOMIZERNNDHEAT _ ,, _L,__,, ,_ GRROREER
PUMP!DUALFUEL UNITS, EQUIP GND l I I I It I \ ORN ORANGE
9, WHENECONOMIZERAND ECONOMIZERRELAYS ARE USED, INSTALL .... _..... / I _Ek--_ _ PNK PINK
WIRES AS sHOWNONTO THE COILS OF BELAYR AND RELAY R1. _/ I I I \I/RED RED
IO.DEHUM FEATURE CANNOTBE USEDWHENECONOMIZERIS INSTALLED. _/ I BU_J" VIO VIOLET
UNIT FNOTORY-SHIPPEU IN GTD MOUE. _ I - _ _-.._./ ^ WHT WHITE
I j COMP YEL YELLOW
LEGEND I--RED_ _OHPRESSOR PLUG
f', FIELD SPLICE DB DEBUMIDIEICNIION MODE I o.. 1I
C) TERMINAL (MARRED) DEHUM DEHUMIDIFICATION HOOE IIOL__ I
= TERMINAL (UNMARKED) DR DEFROST RELAY I I I
• SPLICE EDON ECONOMIZER I_1 FU1 5 AMP _I
0 SPLICE (MARRED) EQUIP EQUIPMENT IHk _ I_YEL, _ IF_
1FACTORYWIRING FU FUSE I •. , I I'-- _I_1
---- FIELDCONTROLWIRING GND GROUND I 9r4 FU25 AMP I_' / _N I--I--7""_ /_
1FIELD POWER WIRING HPS HIGH PRESSURE SYZTCH IB[K RED -- / _RR/YEL_ G F-I/ I\
--- ACCESSORY OR OPTIONAL HR HEATER RELAY I_ _ YEL _r_l L _
WIRING IFB INDOOR FAN BOARD I ' .L ii/// I I _I\I/_\
IFM INDOOR FAN MOTOR I I" I I I I'--I_ _ _X,
AT AUTO TRANSFORMER LPS LOW PRESSURE SWITCH IRED . I I I _ _ \t
4BOY-2SOV OrB OUTDOORrANMOTOR I I I I r--BLK+BLI _I \ _, II
C CONTACTOR OFR OUTDOORFANRELAY I_ _ sMv z_ov I "l III
CAPI CAPACITOR,CQMP RVS REVERSINGV_,LVE I(-3-3 (-T% (3% _I
CCH CRANK CASE HEATER TRAN TRANSFORMER I_ _ _ _ I
COHP COMPRESSORMOTOR T-STAT THERMOSTAT I I
DB DEFROST BOARD R ECONRELAY IB'RN I I I I
DFT DEFROST TEMPERATURE R1 ECON RELAY IAHT(_TRANSF(_PMFR I RI'ul I I
SWITCH STD $_ANDARD MODE I................. I_1 II
' u .T. ORN -- IROTE
y}__zL GHy..J LRED -- --
zF,, I1 1 BRN 1
oItI_-_'_RED- ' -- RED _ -_
I_---_BRN- 1 ,'_....
y$ __L-- yEL- 1
g--_GRN-
^_EeSQEYELECTRICH_T_ ml_BLU
.- HRI (5lw_--___ _ -- -- -- ZR_- + - _,.._ WriT
.Wal ..... _ --Emil-- V--LJ-_-_VIO I
HRI,_,E = 4 tic U+)'-'I_ v -" "_] I
Egl,2 & _{15 EW) I:,._.,._.,._.,."1"
'-
el.
BRN c 2
WHT VIO w_
PNR _oY
SEE SEE NOTE IHRN
NOTE ?
GLU.-.-_BRN •I
-RLU I_-_Ie LU"_\__ _li
o_rWOST,H "°_r_(ml,_ -BRN
FOR WIRING WITH ,,,l_l,,Dl_
ELECTRIC HEATERS LPD
ON HEATER ACCESSORY.
__ I II
- --1_-4 I
i@- -_ _j DIP SWITCH SETTINGS _DEFkULT _ SPEED JUMPERED TEST PINS (USE METAL
"--I-"..__- ---l-----i-'l ao MINUTEG 6e MINUTES NO MINUTES I_0 MINUTES OBJECT) FIELD SPEED-UP CYCLE
' ,", 30 _0
_--_- _T -Tf
__--' OR OR OR I ) MOMENTARILY SHORT PINS AND RELEASE TO BYPASS
COMPRESSOR OFF DELAY.
_i'-J-__--E) F _ _ ICOOLING FAN LOGIC ?) SHORT FOR 5+ DEC. AND RELEASE FOR FORCED DEFROST.
._, ----'-_'. I I __T_RO'I"I3)PERMANENTSHORTWILLBEIGNORED.
IL1-----E)'I-_ --J ENERGIZED DE-ENERGIZED _Ir' DEFROST WILL TERMINATE IN 30 GEC. IF DFT OPEN.
DEFROST WILL TERMINATE NORMALLY IF DFT IS CLOSED.
''"- __-- _,__-_IHEATING FAN LOGIC FIELD DELECTABLE OPTIONS FOR TIME PERIOD
E _._ __ _,.jL,_._ _+ BETWEEN DEFROST CYCLES {MINUTES) THE COMPRESSOR WILL SHUT OFF FOR 3D DEC. ON DEFROST
INITIATION AND TERMINATION IN THE 'QUIET SHIFT' ON
ENERGIZED DE-ENERGIZED POSITION
A10195
Fig. 13 -Connection Wiring Diagram 460-3-60
16

LADDER WIRING DIAGRAM
DANGER ELECTRICAL SHOCK HAZARD DISCONNECT POWER BEFORE SERVICING
UNITCOMPONENTARRANGEMENT
_'mo_ e^w
gDmee^w M'I_Lnix,_r_'_'T--_'l
Ecnow
I_Dm ......._ _"_"fi_'+"
_.l_'l.IkTI
;EE lEA1'!
_mATIC
_ime_lelw|
i
epel_e
z'ixow
_n
c _
T 'STAT
R - -'_RED--
C _ Z_BRN_-
Y1 - -'_YEL--
G--Z'_L-.-GR N--
DH- -Z_-.- BLU--
W - -ZJZ_---WHT--,
IFB
TO ACC¥
HEATER
V- -_--- VIO-
0- -ZT_J---ORN-
Y2- -I
ORY
L__
--BRN-
--WHT-
--VIO-
--PNK-
--GRY-
LI BLKI USE COPPERFIELDCONDUCTORSsuPPLyONLY G/Y_I_i Y_ILL3
460 VAC, 60 HZ, 3PH ---
11
CCH
c 21 _irUSED_/ 2_ c
"_'--9--RE'>--'--'+"_'NV'I--+'_9"
1 OFR A LGRM I
BRN Y.EL,--/-7
IK i__ BLU
AUTDTRANSPORMER
PRIMARY4{OV- SECONDARY230V
SEE NOTE 5 B[K Y_L SEE NOTE 5
Ll
11
"--_4VeoQ [w1_y
11
-0P1-1 "RI' 3A
-OP1-2 "C"
-C) P1-311y1/yi
P1-4"G"
_P1-5"Y2/DH'
P1-6"W2"
-0 P1-?IIW3II
P2-I lC 110
P2-2,,y,,0
OY P2-3'IwI'O
p_i_IRII 0
LOW0
STD_
DEHUMoL.oJ
HIGHO
O P4ilIC II
_P4-2'W2"
_P4-3IW2 '
'OP4-4IW3"
,,OP4-SIW311
460V TRAN 460V
•BLK PRINARY460V YEL,
+_SEE NOTE 6
I
I
I
I
,. I
I
I
I
6
--BRN
ED . I
_SEE
NOTE 10L
L_
.RED_ BRN'
DB DFT
P'-_-_i-----_
P3-zO-- I
TIO'--BLU •BLK_
ORN--OP118,0
RED--OpIIT.R _SEE NOTE 9
WHT--OP1-6.W2
i'_ YEL--OPI-5,Y R
II o.o+
II
I I -- RVS
ISEE NOTE 4 --__
!r--- zo_xK IFM )--BRN--
I __°L,_
_SEE NOTE 7
l I
13
IL2
BLU
13
IFB
'C
'C
IFB-C
DB-C
IFB
)COM
IFB P1-2
[CON I _
PLUG I II _'qll-"l-YEL--i-:-'qD._i._
YEL I
BR IIFB
I ;Z_I;_------'°LL_Z_II_-"L /, BRN-' L
L--_RY7 SEENOTE_/! I 50EZ500554 I E
A10195
Fig. ]3 (:ont. - Ladder Wiring I)ia_P_m 4_0-3-_0
17

PRE-START-UP
FIRE, EXPLOSION, ELECTRICAL 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.
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 (see Fig. 20).
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.
(20 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 5minutes have elapsed. The
defrost board has a built-in 5minute 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 Puron (R-410A) refrigerant, using an
electronic scale. Refer to unit rating plate for required
charge.
Step 2 1 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.
18

50EZ-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 airflow.
c. ELECTRIC HEATING MODE
(1.) Thermostat closes circuit R to W/WI, 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 51. The
compressor, indoor and outdoor fans are energized.
e. HEAT PUMP HEATING WITH AUXILIARY
ELECTRIC HEAT
(1.) Thermostat closes circuits R to G, R to Y and R to
W/WI 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 satisfed during defrost, unit will shut
down and restart in defrost on next call for heat.
Checkin_ and Adiustin_ Refrigerant Charge
The refrigerant system is fully charged with Puron (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 Puron
(R-410A) charge.
A subcooling charging chart is attached to the inside of the
compressor access panel (see Fig. 20). 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. 17).
6. Compare actual liquid line temperature with desired liquid
line temperature. Using a tolerance of -2°F (-I.I°C), add
refrigerant if actual temperature is more than 2°F (I.I°C)
higher than proper liquid line temperature, or remove
refrigerant if actual temperature is more than 2°F (I.I°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.
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.
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
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) (See. Fig. 15). 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) (See Fig. 15).
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 6 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) (See Fig. 15) 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.
19
g

g
Two Cooling Fan Speeds Set-up (Dehumidification
feature used)
IMPORTANT: Dehumidification control must open control
circuit on hunfidity rise above set point.
Use of the dehunfidification cooling fan speed requires use of
either a 24 VAC dehumidistat or a thermostat which includes
control of a 24 VAC dehunfidistat connection, In either case, the
dehunfidification control must open the control circuit on hunfidity
rise above the dehunfidification set point,
1. Using Fig. 15, move the two pin DEHUM jumper from the
"STD" position to the "DEHUM" position.
2. Remove fan speed tap wire from the "LOW" ternfinal on
the interface fan board (IFB) (See Fig. 15).
3. Deternfine correct normal cooling fan speed for unit and
application. Add the wet coil pressure drop in Table 6 to
the system static to deternfine the correct cooling airflow
speed in Table 4 that will deliver the nonfinal 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.
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 deternfine allowable
speeds for the dehunfidification cooling fan speed. In Table
4, speeds that are not allowed for dehunfidification cooling
are shaded.
6. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 3 for color coding) for the dehunfidification
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 dehunfidification cooling.
7. Use any spare vinyl plugs to cap any unused speed tap
wires.
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
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. Using Fig. 15, move the two pin DEHUM jumper from the
"STD" position to the "DEHUM" position.
2. See Table 2 for nfininmm airflow for electric heat operation.
Add electric heater and filter pressure drop to duct system
static pressure to deternfine 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).
[]NIT OPERATION HAZARD
Failure to follow this caution may result in unit component
damage or improper operation.
To use this mode, a speed connection nmst be made on the
"HIGH" ternfinal that meets or exceeds the nfininmm
airflow found in Table 2.
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal
iniury or death.
Disconnect electrical power to the unit and install lockout
tag before changing blower speed.
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. 15).
_- OUTDOOR COIL
LEGEND
HPS High Pressure Switch
LCS Loss of Charge Switch
Accurate€Metering Device
] Arrow indicates direction of flow
Bypass
Position
Fig. 14 - Typical Heat Pump Operation, Cooling Mode
INDOOR COIL
P
P
C03011
20