38YRA
Heat Pump—Outdoor Section
Installation and Start-Up Instructions
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since last issue.
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause personal injury or property damage.
Consult a qualified installer, service agency, or your distributor or
branch for information or assistance. The qualified installer or
agency must use factory-authorized kits or accessories when
modifying this product. Refer to the individual instructions pack-
aged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for brazing operations. Have fire extinguisher
available. Read these instructions thoroughly and follow all
warnings or cautions attached to the unit. Consult local building
codes and the National Electrical Code (NEC) for special instal-
lation requirements.
Recognize safety information. This is the safety-alert symbol
When you see this symbol on the unit or in instructions and
manuals, be alert to the potential for personal injury.
.
A92446
Fig. 1—Model 38YRA
clearance on 1 side of unit and 12 in. on all remaining sides must
be maintained. Maintain a distance of 24 in. between units.
Position so snow, ice, and water from roof or eaves cannot fall
directly on unit.
Understand the signal word DANGER, WARNING, or CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies hazards which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage.
On rooftop applications, locate unit at least 6 in. above roof
surface. Place unit above a load-bearing wall and isolate unit and
tubing set from structure.
Arrange supporting members to adequately support unit and
minimize transmission of vibration to building. Consult local
codes governing rooftop applications.
Before installing or servicing system, always turn off main
power to system. There may be more than 1 disconnect
switch. Turn off accessory heater power if applicable. Elec-
trical shock can cause personal injury or death.
Step 3—Elevate Unit
For proper drainage the heat pump must be raised off the mounting
surface. Fig. 4 shows unit with accessory support feet installed.
Use accessory heat pump snow rack in areas where prolonged
subfreezing temperatures or heavy snow occur. Refer to separate
Installation Instructions packaged with the accessories.
INSTALLATION
Step 1—Check Equipment and Jobsite
UNPACK UNIT — Move to final location. Remove carton taking
care not to damage unit.
INSPECT EQUIPMENT — File claim with shipping company,
prior to installation, if shipment is damaged or incomplete. Locate
unit rating plate on unit corner panel. (See Fig. 2.) It contains
information needed to properly install unit. Check rating plate to
be sure unit matches job specifications.
For proper unit operation and reliability, this unit must be
installed with the field-supplied balance port, hard shut-off
TXV. Do not install with evaporator coils having capillary
tube metering devices.
Step 2—Install on a Solid, Level Mounting Pad
Step 4—Remove Indoor AccuRater® Piston and Install
TXV
If conditions or local codes require the unit be attached to pad,
tie-down bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 2
to determine base pan size and knockout hole location.
After removing existing AccuRater from indoor coil, install
field-supplied bi-flow hard shut-off TXV kit. (See Fig. 5 and 6.)
For TXV kit part number and charging instruction, refer to TXV
label in your unit. If the indoor unit (fan coil) comes factory-
equipped with a bi-flow hard shut-off TXV, no TXV change is
required.
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30-in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a 6-in.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 5a 5a
1
4
PC 101
Catalog No. 533-890
Printed in U.S.A.
Form 38YRA-2SI
Pg 1
8-95
Replaces: 38YRA-1SI
7. Do not suspend refrigerant tubing from joists and studs with a
rigid wire or strap which comes in direct contact with the
tubing. (See Fig. 3.)
NOTE: Avoid contact between tubing and structure
OUTDOOR WALL
CAULK
INDOOR WALL
LIQUID TUBE
VAPOR TUBE
JOIST
INSULATION
THROUGH THE WALL
A93567
Fig. 4—Accessory Support Feet
HANGER STRAP
(AROUND VAPOR
TUBE ONLY)
INSULATION
VAPOR TUBE
COIL
SENSING
BULB
EQUALIZER
TUBE
1″ MIN.
LIQUID TUBE
SUSPENSION
THERMOSTATIC
EXPANSION
VALVE
A94028
→ Fig. 3—Piping Installation
8. Ensure that tubing insulation is pliable and completely sur-
rounds the vapor tube.
A88382
Fig. 5—Typical TXV Installation
9. When necessary, use hanger straps which are 1 in. wide and
conform to the shape of the tubing insulation. (See Fig. 3.)
10 O'CLOCK
2 O'CLOCK
10. Isolate the hanger straps from the insulation by using metal
sleeves bent to conform to the shape of the insulation.
SENSING BULB
If refrigerant tubes or indoor coil is exposed to atmospheric
conditions for longer than 5 minutes, it must be evacuated to 500
microns to eliminate contamination and moisture in the system.
STRAP
OUTDOOR UNITS CONNECTED TO FACTORY-APPROVED
INDOOR UNITS — Outdoor unit contains correct system refrig-
erant charge for operation with indoor unit of the same size when
connected by 15 ft of field-supplied or factory accessory tubing.
Check refrigerant charge for maximum efficiency. (See Step
10—Checking Charge.)
SUCTION TUBE
8 O'CLOCK
7⁄8 IN. OD & SMALLER
4 O'CLOCK
LARGER THAN 7⁄8 IN. OD
REFRIGERANT TUBING — Connect refrigerant tubing to fit-
tings on outdoor unit vapor and liquid service valves. (See Fig. 2.)
A81032
Fig. 6—Positioning of Sensing Bulb
Table 1—Refrigerant Connections and Recom-
mended Liquid and Vapor Tube Diameters (In.)
To avoid valve damage while brazing, service valves must be
wrapped with a heat sinking material such as a wet cloth.
LIQUID
Connect
VAPOR
Connect
UNIT
SIZE
SWEAT CONNECTION — Use refrigerant grade tubing. Service
valves are closed from factory and ready for brazing. After
wrapping the service valve with a wet cloth, the tubing set can be
brazed to the service valve using either silver bearing or non-silver
bearing brazing material. Remove plastic retainer holding outdoor
piston in the liquid service valve and connect sweat adapter
provided to valve. (See Fig. 7.) Consult local code requirements.
Refrigerant tubing and indoor coil are now ready for leak testing.
This check should include all field and factory joints.
Tube
Tube
Diameter
Diameter
Diameter
Diameter
→ 018
024-030
036-048
060
3/8
3/8
3/8
3/8
3/8
5/8
5/8
3/4
3/8
3/4
3/8
7/8
7/8
3/8
7/8
1-1/8
Note: Tube diameters are for lengths up to 50 ft. For tubing lengths greater
than 50 ft, consult Long-Line Application Guideline.
3
NOTE: Install branch circuit disconnect per NEC of adequate
size to handle unit starting current. Locate disconnect within sight
from and readily accessible from unit, per Section 440-14 of NEC.
INSIDE STRAINER
FLARE NUT
ROUTE GROUND AND POWER WIRES — Remove access
panel and control box cover to gain access to unit wiring. Extend
wires from disconnect through power wiring hole provided and
into unit control box. (See Fig. 2.)
FLARE ADAPTER
CONNECT GROUND AND POWER WIRES — Connect ground
wire to ground connection in control box for safety. Connect
power wiring to contactor as shown in Fig. 8.
PISTON RETAINER
PISTON
CONNECT CONTROL WIRING — Route 24-v control wires
through control wiring grommet and connect leads to control
wiring terminal board. (See Fig. 9.)
Use No. 18 AWG color-coded, insulated (35° C minimum) wires.
If thermostat is located more than 100 ft from unit (as measured
along the control voltage wires), use No. 16 AWG color-coded
wires to avoid excessive voltage drop.
LIQUID SERVICE VALVE
A92464
Use furnace transformer, fan coil transformer, or accessory trans-
former for control power, 24-v/40va minimum.
→ Fig. 7—Service Valve with Sweat Adapter Tube
NOTE: Use of available 24-v accessories may exceed the mini-
mum 40-va power requirement. Determine total transformer load-
ing and increase the transformer capacity or split the load with an
accessory transformer as required.
A brazing shield MUST be used when tubing sets are being
brazed to the service valves to prevent damage to the painted
unit surface.
NOTE: The defrost timer is factory set for 90-minute cycles. The
timer can be field set for 30- and 50-minute cycles depending on
defrost conditions in your geographical location.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal to avoid personal injury or death.
Use all service ports and open all flow-control devices,
including solenoid valves.
DISCONNECT
PER N.E.C. AND/OR
LOCAL CODES
CONTACTOR
Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
FIELD POWER
WIRING
BLUE
3 PHASE ONLY
Step 7—Make Electrical Connections
FIELD GROUND
WIRING
GROUND
LUG
To avoid personal injury or death, do not supply power to unit
with compressor terminal box cover removed.
A94025
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit
protection device.
→ Fig. 8—Line Power Connections
Step 8—Install Electrical Accessories
Refer to the individual instructions packaged with the kits or
accessories when installing.
According to NEC, ANSI/NFPA 70, and local codes, the
cabinet must have an uninterrupted or unbroken ground to
minimize personal injury if an electrical fault should occur.
The ground may consist of electrical wire or metal conduit
when installed in accordance with existing electrical codes.
Failure to follow this warning could result in an electric
shock, fire, or death.
Damage may occur to the scroll compressor if operated at a
negative suction pressure during a system pumpdown.
Step 9—Start-Up
1. Fully back seat (open) liquid and vapor tube service valves.
2. Unit is shipped with valve stem(s) front seated and caps
installed. Replace stem caps after system is opened to refrig-
erant flow (back seated). Replace caps finger tight and tighten
additional 1/12 turn using a backup wrench on valve body flats
to prevent distortion of sheet metal.
NOTE: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage or phase imbalance may
fluctuate above or below permissible limits.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature.
NOTE: Use copper wire only between disconnect switch and
unit.
4
5. Set room thermostat at HEAT or COOL and fan switch at ON
or AUTO, as desired. Operate unit for 15 minutes. Check
system refrigerant charge. (See Step 10.)
The defrost mode is identical to the cooling mode except the
outdoor fan motor stops and a second-stage heat is turned on to
continue warming the conditioned space.
SEQUENCE OF OPERATION — With power supplied to indoor
and outdoor units, transformer is energized.
Step 10—Checking Charge
Cooling
On a call for cooling, the thermostat makes circuits R-O, R-Y, and
R-G. Circuit R-O energizes the reversing valve, switching it to
cooling position. Circuit R-Y energizes the contactor, starting
outdoor fan motor and compressor circuit. R-G energizes the
indoor unit blower relay, starting the indoor blower motor on high
speed.
Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
Factory charge is shown on unit rating plate. (See Fig. 2.)
When the thermostat is satisfied, its contacts open, de-energizing
the contactor and blower relay. Compressor and motors should
stop.
Service valve gage ports are not equipped with Schrader
valves. To prevent personal injury, make sure valves are fully
back seated before removing gage port caps. Wear safety
glasses and gloves when handling refrigerant.
Heating
On a call for heating, the thermostat makes circuits R-Y and R-G.
Circuit R-Y energizes contactor, starting outdoor fan motor and
compressor. Circuit R-G energizes the indoor blower relay, start-
ing the blower motor on high speed.
Compressor damage may occur if system is overcharged.
Should the temperature continue to fall, R-W2 is made through the
second-stage room thermostat bulb. Circuit R-W2 energizes a
sequencer, bringing on the first bank of supplemental electric heat
and providing electrical potential to the second heater sequencer (if
used). If the outdoor temperature falls below the setting of the
outdoor thermostat (field-installed option), the contacts close to
complete the circuit and bring on the second bank of supplemental
electric heat.
Adjust charge in cooling mode by following procedure shown on
the subcooling charging tables located on unit information plate.
Check charge in heating mode by following procedure shown on
heating check chart located on unit information plate.
CARE AND MAINTENANCE
For continuing high performance and to minimize possible equip-
ment failure, it is essential that periodic maintenance be performed
on this equipment. Consult your servicing contractor or User’s
Manual for the proper frequency of maintenance. Frequency of
maintenance may vary depending upon geographic areas, such as
coastal applications.
When the thermostat is satisfied, its contacts open, de-energizing
the contactor and sequencer. All heaters and motors should stop.
Defrost
The defrost control is a time/temperature control which includes a
field-selectable (quick connect pins located at edge of circuit
board) time period between defrost cycles (30, 50, and 90
minutes), factory set at 90 minutes.
Step 1—Leave User’s Manual with Homeowner
The electronic timer and the defrost cycle will start only when the
contactor is energized and the defrost thermostat is closed.
Explain system operation and maintenance procedures outlined in
User’s Manual.
5
TWO-STAGE OR
VARIABLE SPEED
FURNACE
DUAL FUEL
THERMOSTAT
SINGLE-SPEED
HEAT PUMP
DUAL FUEL
THERMOSTAT
SINGLE-STAGE
FURNACE
SINGLE-SPEED
HEAT PUMP
24 VAC HOT
FAN
R
R
G
R
G
24 VAC HOT
R
G
R
G
R
W2
Y
W/W1
Y/Y2
W/W1
FURNACE LO
COMPRESSOR
RVS COOLING
FURNACE HI
FAN
Y/Y2
O
W2
Y
W/W1
Y/Y2
W
Y
FURNACE
COMPRESSOR
RVS COOLING
O/W2
O
W2
Y1/W2
O/W2
O
Y1
C
Y1/W2
N/A
24 VAC COM
RVS HEATING
RVS SENSING
C
C
24 VAC COM
C
C
C
B
L
RVS HEATING
RVS SENSING
B
L
SEE NOTES 1 AND 2
SEE NOTE 1
OUTDOOR
S1
S2
OUTDOOR
SENSOR
OUTDOOR
TEMPERATURE
SENSOR
S1
S2
OUTDOOR
SENSOR
TEMPERATURE
SENSOR
CONNECTION
CONNECTION
A95216
A95215
CORPORATE
PROGRAMMABLE
THERMOSTAT
MODEL HP
CORPORATE
NON-PROGRAMMABLE
THERMOSTAT
FA, FB, FC,
FD, FF
HEAT
PUMP
FA, FB, FC,
FD, FF
FAN COIL
FAN COIL
HEAT
PUMP
MODEL HP
24 VAC HOT
R
R
R
G
24 VAC HOT
R
R
R
C
INDOOR FAN
G
24 VAC COM
C
C
HEAT STAGE 2
W/W1
W2
W2
HEAT STAGE 2
W/W1
W2
W2
COOL/HEAT
STAGE 1
Y/Y2
Y
COOL/HEAT
STAGE 1
Y/Y2
G
Y
O/W2
O
RVS COOLING
NOT USED
G
INDOOR FAN
Y1/W2
C
O/W2
Y1
O
RVS COOLING
NOT USED
NOT USED
TROUBLE
C
C
24 VAC COM
NOT USED
TROUBLE
B
L
B
L
OPTIONAL
OUTDOOR
SENSOR
S1
S2
OPTIONAL
OUTDOOR
SENSOR
S1
S2
CONNECTION
CONNECTION
A94390
A94391
→ Fig. 9—Typical 24-v Circuit Connections
6
CORPORATE
NON-PROGRAMMABLE
THERMOSTAT
FK4B
FAN COIL
HEAT
PUMP
MODEL HP
24 VAC HOT
R
C
R
R
CORPORATE
PROGRAMMABLE
THERMOSTAT
MODEL HP
24 VAC COM
C
C
FK4B
FAN COIL
HEAT
PUMP
HEAT STAGE 2
W2
W/W1
W2
24 VAC HOT
R
G
R
R
COOL/HEAT
STAGE 1
Y/Y2
G
Y/Y2
Y
INDOOR FAN
G
W2
Y
HEAT STAGE 2
W/W1
W2
G
W3
O
INDOOR FAN
COOL/HEAT
STAGE 1
Y/Y2
Y/Y2
O
O/W2
RVS COOLING
NOT USED
NOT USED
TROUBLE
O/W2
RVS COOLING
NOT USED
O
O
Y1
B
Y1
E
Y1/W2
W3
C
C
C
24 VAC COM
NOT USED
TROUBLE
L
L
E
L
B
L
OPTIONAL
OUTDOOR
SENSOR
S1
S2
OPTIONAL
OUTDOOR
SENSOR
CONNECTION
S1
S2
CONNECTION
A94392
A94393
CORPORATE
NON-PROGRAMMABLE
THERMOSTAT
FK4C
CORPORATE
PROGRAMMABLE
THERMOSTAT
MODEL HP
HEAT
PUMP
MODEL HP
FAN COIL
FK4C
FAN COIL
HEAT
PUMP
24 VAC HOT
R
R
R
24 VAC COM
24 VAC HOT
R
G
R
R
C
C
C
INDOOR FAN
G
HEAT STAGE 2
W2
W/W1
W1
W2
Y
HEAT STAGE 2
W/W1
Y/Y2
W1
COOL/HEAT
STAGE 1
Y/Y2
Y/Y2
Y
COOL/HEAT
STAGE 1
Y/Y2
G
G
W2
O
INDOOR FAN
O/W2
RVS COOLING
NOT USED
O
O
Y1/W2
W2
O
O/W2
RVS COOLING
C
C
C
NOT USED
24 VAC COM
NOT USED
TROUBLE
Y1
Y1
NOT USED
B
L
B
L
TROUBLE
OPTIONAL
OUTDOOR
SENSOR
S1
S2
OPTIONAL
OUTDOOR
SENSOR
S1
S2
CONNECTION
CONNECTION
A95330
A95331
→ Fig. 9—Typical 24-v Circuit Connections (continued)
7
NON-CORPORATE
NON-PROGRAMMABLE
THERMOSTAT
FK4B
FAN COIL
HEAT
PUMP
MODEL HP
NON-CORPORATE
NON-PROGRAMMABLE
THERMOSTAT
24 VAC HOT
R
C
R
R
FA, FB, FC,
FD, FF
HEAT
PUMP
24 VAC COM
FAN COIL
C
MODEL HP
C
24 VAC HOT
R
R
R
C
HEAT STAGE 2
W2
W
W2
C
W2
Y
C
24 VAC COM
COOL/HEAT
STAGE 1
Y
Y/Y2
Y
HEAT STAGE 2
W
Y
W2
G
G
W3
O
INDOOR FAN
COOL/HEAT
STAGE 1
O
O
RVS COOLING
G
O
G
INDOOR FAN
Y1
E
RVS COOLING
O
EMERGENCY
HEAT
E
EMERGENCY
HEAT
E
L
A95279
A95280
→ Fig. 9—Typical 24-v Circuit Connections (continued)
WIRING DIAGRAM NOTES:
1. Underlined letter on dual terminal indicates its usage.
Outdoor Temperature Sensor must be attached in all dual fuel installations.
Jumper wire between O/W2 and L thermostst terminals MUST be present.
2. Y1 and O connections to 2-stage furnaces MAY NOT EXIST, or may be only a wire rather than a screw terminal.
3. Corporate thermostat model numbers begin with TSTAT_______.
4. Wiring must conform to NEC or local code.
5. To stage the electric resistance heat, consult outdoor thermostat installation instructions.
Copyright 1995 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
38yra2si
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 5a 5a
1
4
PC 101
Catalog No. 533-890
Printed in U.S.A.
Form 38YRA-2SI
Pg 8
8-95
Replaces: 38YRA-1SI
|