Carrier 38QR018C-060C Dimensions and installation guide

Installation, Start-Up and Service
Instructions
CONTENTS Page
SAFETY CONSIDERATIONS .................. 1
INSTALLATION ............................ 1-6
Step 1 — Complete Pre-Installation Checks . .. 1-4
• UNPACK UNIT
• INSPECT SHIPMENT
• CONSIDER SYSTEM REQUIREMENTS
• CHECK ACCURATER® METERING DEVICE
Step 2 — Rig and Mount Unit ................ 4
• MOUNTING ON GROUND
• MOUNTING ON ROOF
• RIGGING
Step 3 — Complete Refrigerant
Piping Connections ........................ 4,5
• INSTALL FILTER DRIER AND MOISTURE
INDICATOR
• MAKE PIPING SWEAT CONNECTIONS
• PROVIDE SAFETY RELIEF
Step 4 — Make Electrical Connections ...... 6
• POWER WIRING
• CONTROL CIRCUIT WIRING
START-UP ................................ 6,7
Preliminary Checks ........................ 6
Leak Test .................................. 6
Evacuate and Dehydrate .................... 6
Charge System ............................ 6
To Start Unit ................................ 7
SERVICE ................................ 7-11
MAINTENANCE ............................ 11
TROUBLESHOOTING .................... 12,13
SAFETY CONSIDERATIONS
Installing and servicing air conditioning equipment can
be hazardous due to system pressure and electrical compo-
nents. Only trained and qualified service personnel should
install or service air conditioning equipment.
Untrained personnel can perform basic maintenance, such
as cleaning and replacing filters. All other operations should
be performed by trained service personnel. When working
on air conditioning equipment, observe safety precautions in
literature, tags, and labels attached to unit.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for brazing operations. Have fire ex-
tinguisher available. Read these instructions thoroughly. Con-
sult local building codes and National Electrical Code (NEC)
for special installation requirements.
Before installing or servicing system, always turn off
main power to system. There may be more than one dis-
connect switch. Turn off accessory heater power if ap-
plicable. Electrical shock can cause personal injury.
INSTALLATION
Step 1 — Complete Pre-Installation Checks
UNPACK UNIT (see Fig. 1.) — Move unit to final location.
Remove carton from unit, being careful not to damage serv-
ice valves and grilles.
INSPECT SHIPMENT — File claim with shipping com-
pany if shipment is damaged or incomplete.
CONSIDER SYSTEM REQUIREMENTS — Consult
local building codes and NEC for special installation
requirements.
Allow sufficient space for airflow clearance, wiring, re-
frigerant piping, and servicing unit. See Fig. 2 and 3.
Locate unit so that airflow is unrestricted on both sides.
Refer to Fig. 2 and 3.
Unit may be mounted on a level pad directly on base legs
or mounted on raised pads at support points. See Fig. 2 and
3 for center of gravity.
HEAT PUMP
Fig. 1 — Model 38QR018C-060C
38QR018C-060C
Commercial Heat Pumps
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 5a 5a PC 111 Catalog No. 563-882 Printed in U.S.A. Form 38QRC-1SI Pg 1 3-92 Replaces: New

NOTES:
1. Dimensions in [ ] are in millimeters.
2. Airflow .
3. Center of gravity .
4. Footprint 018C-036C: 3.7 sq ft (.34 m2).
5. Do not use screws longer than
1
⁄
2
in. (13 mm) near return-air opening.
UNIT WEIGHT —
LB (KG) DIMENSIONS — in. (mm)
‘‘A’’ ‘‘B’’ ‘‘C’’
38QR018C 154 (70) 13
(329)
5
⁄
8
(15.88)
3
⁄
8
(9.53)
38QR024C 167 (76)
38QR030C 180 (82)
3
⁄
4
(19.05)
38QR036C 184 (83)
Fig. 2 — 38QR Dimensional Drawing, 018C-036C (Single-Phase Units)
2

NOTES:
1. Dimensions in [ ] are in millimeters.
2. Airflow .
3. Center of gravity .
4. Footprint 048C,060C: 5.3 sq ft (.49 m2).
5. Do not use screws longer than
1
⁄
2
in. (13 mm) near return-air opening.
UNIT WEIGHT —
LB (KG) DIMENSIONS — in. (mm)
‘‘A’’ ‘‘B’’ ‘‘C’’
38QR036C 249 (113) 13
11
⁄
16
(28.97)
7
⁄
8
(22.22)
3
⁄
8
(9.53)
38QR048C 252 (114) 13
11
⁄
16
(28.97)
7
⁄
8
(22.22)
3
⁄
8
(9.53)
38QR060C 272 (123) 14
1
⁄
2
(30.69)
7
⁄
8
(22.22)
3
⁄
8
(9.53)
Fig. 3 — 38QR Dimensional Drawing, 036C (3-Phase Units) and 048C,060C (Single- and 3-Phase Units)
3

CHECKACCURATER® METERING DEVICE — The cor-
rect AccuRater (bypass type) refrigerant control is required
for system capacity optimization.AnAccuRater device with
field-replaceable piston (see Fig. 4) is supplied on indoor coil
and at service valve of outdoor unit. Refer to the AccuRater
metering device table in separate indoor unit installation in-
structions to determine the correct AccuRater piston size re-
quired for the heat pump/indoor unit system being installed.
Note that one of 2 types ofAccuRater controls can be found
on the indoor unit, and that Type B AccuRater devices are
used on 38QR018C-060C heat pumps. Do not interchange
components between the AccuRater device types. Matching
of heat pump with indoor unit may require field replacement
of piston. Replace pistons, if required, before connecting re-
frigerant lines. Piston replacement instructions are included
in separate indoor unit installation instructions.After system
installation is complete, see Refrigerant Charging section on
page 10 to check and/or adjust refrigerant charge.
Step 2 — Rig and Mount Unit
MOUNTING ON GROUND — Mount unit on a solid, level
concrete pad. Position unit so water or ice from roof does
not fall directly onto unit. Use accessory snow rack (part no.
38QR900001 or -011) or ice stand (part no. 38QR900021 or
-031) (see Fig. 2, 3) where prolonged subfreezing tempera-
tures or heavy snow occurs. Refer to separate installation
instructions packaged with the accessories. If conditions or
local codes require unit be fastened to pad, 6 field-supplied
tiedown bolts should be used and fastened through slots pro-
vided in unit mounting feet.
MOUNTING ON ROOF — Mount unit on a level platform
or frame at least 6 in. above roof surface. Isolate unit and
tubing from structure.
RIGGING
Be sure unit panels are securely in place prior to
rigging.
Keep unit upright. Lift unit using sling. Use cardboard or
padding under sling, and spreader bars to prevent sling dam-
age to unit. See Fig. 5. See Fig. 2 and 3 for center of gravity
reference. Install unit so that coil does not face into prevail-
ing winds. If this is not possible and constant winds above
25 mph are expected, use Accessory Wind Baffle (part no.
38QR900041 or -051). See installation instructions pro-
vided with accessory kit.
Step 3 — Complete Refrigerant Piping Connec-
tions — Outdoor units may be connected to indoor units
using field-supplied tubing of refrigerant grade and condi-
tion. See Table 1 for correct line sizes. Do not use less than
10 ft of interconnecting tubing.
DO NOT BURY MORE THAN 36 IN. OF REFRIG-
ERANT PIPE IN THE GROUND. If any section of pipe
is buried, there must be a 6-in. vertical rise to the valve
connections on the outdoor unit. If more than the rec-
ommended length is buried, refrigerant may migrate to
cooler, buried section during extended periods of sys-
tem shutdown. This causes refrigerant slugging and could
possibly damage compressor at start-up.
When more than 50 ft of interconnecting tubing and more
than 30 ft of vertical lift is used, refer to Part 3 of Carrier
System Design Manual for design details, or contact your
local distributor.
TYPE A
NOTE: Arrow on AccuRater body points in free flow direction, away
from the indoor coil.
TYPE B
Fig. 4 — AccuRater® (Bypass Type) Metering De-
vice Components
Fig. 5 — Lifting Unit With Sling
4

If either refrigerant tubing or indoor coil is exposed to at-
mospheric conditions for longer than 5 minutes, it must be
evacuated to 1000 microns to eliminate contamination and
moisture in the system.
Run refrigerant tubes as directly as possible, avoiding un-
necessary turns and bends. Suspend refrigerant tubes so they
do not damage insulation on vapor tube and do not transmit
vibration to structure. Also, when passing refrigerant tubes
through wall, seal opening so that vibration is not transmit-
ted to structure. Leave some slack in refrigerant tubes be-
tween structure and outdoor unit to absorb vibration. Refer
to separate indoor unit installation instructions for addi-
tional information.
INSTALL FILTER DRIER AND MOISTURE INDICA-
TOR — The filter drier is factory supplied and field in-
stalled. Moisture indicator (sight glass) is a field-supplied
option and should be installed just after liquid line shutoff
valve. Do not use a receiver (a receiver is not provided with
unit and one should not be used).
MAKE PIPING SWEAT CONNECTIONS — Remove plas-
tic caps from liquid and suction service valves. Use refrig-
erant grade tubing. Service valves are closed from the fac-
tory and are 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 bear-
ing brazing material. Consult local code requirements.
Refrigerant tubing and indoor coil are now ready for leak
testing.
NOTE: Unit is shipped with R-22 factory holding charge
indicated on nameplate.
Pass nitrogen or other inert gas through piping while brazing
to prevent formation of copper oxide.
To avoid damage while brazing, service valves should
be wrapped with a heat-sinking material such as a wet
cloth.
When brazing tubing sets to the service valves, a braz-
ing shield MUST be used to prevent damage to the painted
unit surface.
PROVIDE SAFETY RELIEF —Afusible plug is located in
unit suction line; do not cap this plug. If local code requires
additional safety devices, install as directed.
Table 1 — Physical Data
Unit 38QR 018C-3 024C-3 030C-3 036C-3 036C-5,6 048C-3,5,6 060C-3,5,6
Operating Weight (lb) 154 167 180 184 249 252 272
Refrigerant R-22
Compressor Hermetic
Type Reciprocating Scroll Reciprocating
Model Tecumseh Tecumseh Copeland Copeland Copeland Tecumseh Copeland
AW5519G AW5524G ZR28KI-PFV ZR34KI-PFV CRH3-0275 AV5549G CRP5-0450
Oil (pt) — Initial/Recharge 32/30 32/30 28/24 34/30 55/51 54/50 70/66
Crankcase Heater Watts 19 19 — — 40 27 40
Outdoor Fan Propeller Type, Direct Drive, Horizontal
Rpm 850 850 850 850 850 850 850
Diameter (in)-no. of Blades 18-3 18-3 18-3 18-3 24-3 24-3 24-3
Fan Pitch (Deg) 25 27 27 31 24 24 24
Motor Hp
1
⁄
81
⁄
81
⁄
81
⁄
81
⁄
41
⁄
41
⁄
4
Nominal Airflow (cfm) 1720 1720 1720 1720 3900 3900 3900
Outdoor Coil Copper Tube, Aluminum Plate Fin
Face Area (Sq Ft)/Rows 6.1/1.5* 6.1/2 6.1/3 6.1/3 12.3/2 12.3/2 12.3/3
Fins./in. 15 15 15 15 15 15 15
Line Sizes† — (in. OD)
Vapor
5
⁄
85
⁄
83
⁄
43
⁄
43
⁄
4
1
1
⁄
8
1
1
⁄
8
Liquid
3
⁄
83
⁄
83
⁄
83
⁄
83
⁄
83
⁄
83
⁄
8
Valve Connection — ODF (in.)
Vapor
5
⁄
85
⁄
83
⁄
43
⁄
47
⁄
87
⁄
87
⁄
8
Liquid
3
⁄ 83 ⁄ 83 ⁄ 83 ⁄ 83 ⁄ 83 ⁄ 83 ⁄ 8
Controls — Pressurestat Settings
High Cutout (psig) 426 67
High Cut-in (psig) 320 620
Low Cutout (psig) 763
Low Cut-in (psig) 22 65
Fusible Plug 210 F
*The second row of the coil is one half of the height of the first row.
†Line sizes are for runs up to 25 ft.
5

Step 4 — Make Electrical Connections
Unit cabinet must have an uninterrupted, unbroken elec-
trical ground to minimize the possibility of personal in-
jury if an electrical fault should occur. This ground may
consist of electrical wire connected to unit ground lug
in control compartment, or conduit approved for elec-
trical ground when installed in accordance with NEC,
ANSI/NFPA (American National Standards Institute/
National Fire Protection Association) 70-1987 and lo-
cal electrical codes. Failure to follow this warning could
result in the installer being liable for personal injury of
others.
Unit failure as a result of operation on improper line
voltage or excessive phase imbalance constitutes abuse
and may cause damage to electrical components. Such
operation would invalidate any applicable Carrier
warranty.
POWER WIRING — Unit is factory wired for voltage shown
on nameplate. Provide adequate fused disconnect switch within
sight from unit, readily accessible, but out of reach of chil-
dren. Provision for locking switch open (off) is advisable to
prevent power from being turned on while unit is being ser-
viced. Disconnect switch, fuses, and field wiring must com-
ply with NEC and local code requirements. Use copper wire
only between disconnect switch and unit. Use minimum
60 C wire for field power connection.
Route power wires through opening in unit side panel and
connect in unit control box as shown on unit label diagram
and Fig. 6 and 7. Unit must be grounded.
CONTROL CIRCUIT WIRING — Control voltage is 24 v
(40 va minimum). See Fig. 7 and unit label diagram for field-
supplied wiring details. Route control wires through open-
ing in unit side panel to connection in unit control box.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (Ameri-
can Wire Gage) insulated wire (35 C minimum) For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum). For
over 75 ft, use 14 AWG insulated wire (35 C minimum).
NOTE: Operation of unit on improper line voltage consti-
tutes abuse and could affect Carrier warranty. See Table 2.
Do not install unit in system where voltage may fluctuate
above or below permissible limits.
See Table 2 for recommended fuse sizes. When making
electrical connections, provide clearance at unit for refrig-
erant piping connections.
Use indoor unit transformer as 24-v (40-va minimum) sup-
ply for system or use accessory transformer.
Before performing service or maintenance, be sure in-
door unit main power switch is turned OFF and indoor
blower has stopped. Failure to do so may result in elec-
trical shock, or injury from rotating fan blades.
START-UP
Preliminary Checks
1. Check that all internal wiring connections are tight and
that all barriers, covers, and panels are in place.
2. Field electrical power source must agree with unit name-
plate rating.
3. All service valves must be open.
4. Belly-band crankcase heater must be tight on compressor
crankcase for those units with belly-band heaters.
LeakTest — Field piping and fan coil must be leak tested
by pressure method described in Carrier Standard Service
Techniques Manual, Chapter 1, Section 1-6. Use R-22 at ap-
proximately 25 psig backed up with an inert gas to a total
pressure not to exceed 245 psig.
Before starting unit, crankcase heater must be on for
12 hours to be sure all refrigerant is out of the oil.
To energize crankcase heater, set space thermostat above
ambient temperature so there will be no demand for cooling.
Close field disconnect. The crankcase heater is now
energized.
Evacuate and Dehydrate — Field piping and fan coil
must be evacuated and dehydrated by either of the methods
described in Carrier Standard Service Techniques Manual,
Chapter 1, Section 1-7.
Service valves must be fully backseated to close service
port. There is no Schrader valve at the service port, and
failure to backseat the valve could result in loss of sys-
tem charge or personal injury.
Charge System — Release holding charge into system
by opening (backseating) liquid and suction line service valves.
Add charge amount as required for the total system. Refer to
indoor unit installation instructions for the required total sys-
tem charge, when connected by 25 ft of tubing.
LEGEND
NEC — National Electrical Code
TB — Terminal Board
TB Connections
Field Wiring
Factory Wiring
Fig. 6 — Line Power Connections
6

To Start Unit — Be sure that crankcase heater has been
on for 12 hours and that field disconnect is closed. Set room
thermostat below ambient temperature. Operate unit for
15 minutes, then check system refrigerant charge. See Re-
frigerant Charging section on page 10.
Unit compressor starts after a 5-minute delay if equipped
with accessory Time Guard® II device (part no. 38HD900021).
See separate accessory installation instructions to install this
accessory. When ambient temperature will fall below 55 F,
accessory low-ambient controller (part no. 38HD900001) is
required.
SERVICE
Before performing recommended maintenance, be sure
unit main power switch is turned off. Failure to do so
may result in electrical shock or injury from rotating fan
blade.
OutdoorFan— Areinforced wire mount holds the outdoor-
fan motor assembly in position. See Fig. 8 for proper mount-
ing positions.
High-Pressure Relief Valve — Valve is located in
compressor. Relief valve opens at a pressure differential of
approximately 450 650 psig between suction (low side) and
discharge (high side) to allow pressure equalization.
InternalCurrent andTemperature SensitiveOver-
load — Control resets automatically when internal com-
pressor motor temperature drops to a safe level (overloads
may require up to 45 minutes to reset). When an internal
overload is suspected of being open, check by using an ohm-
meter or continuity tester. If necessary, refer to Carrier Stand-
ard System Techniques Manual, Chapter 2, for complete
information.
PumpdownProcedure — The system may be pumped
down in order to make repairs on low side without losing
complete refrigerant charge.
1. Attach pressure gage to suction service valve gage port.
2. Frontseat the liquid line valve.
The 38QR018C-060C unit coils hold only the factory-
designated amount of refrigerant. Additional refrigerant
may cause units to relieve pressure through compressor
internal pressure relief valve (indicated by a sudden rise
of suction pressure) before suction pressure reaches
5 psig. If this occurs, shut off unit immediately, front-
seat suction valve, and remove and reclaim excess re-
frigerant following accepted practices.
3. Start unit and run until suction pressure reaches 5 psig or
low-pressure switch opens.
4. Shut off unit and frontseat suction valve.
5. Depressurize low side of unit and reclaim refrigerant fol-
lowing accepted practices.
USED WITH UNITS 40AQ,
40QB/QH, FD3A, FB4A,
FB5A, FK4A, 40DQ AND
40YA/YR/YZ
USED WITH UNITS
FF1A AND 40RC USED WITH UNITS FF1A AND 40RC USED WITH UNITS 40AQ, 40QB/ QH, FD3A, FB4A, FK4A, FB5A,
40DQ, AND 40YA/YR/YZ
NOTE: Remove factory-installed jumpers on indoor unit
terminal board when installing outdoor thermostats.
LEGEND
ODT — Outdoor Thermostat
SHR — Supplemental Heat Relay
Splice Connection
Factory Wiring
Field Wiring Fig.7—Typical Control Circuit Connections
UNIT SIZE-in. (mm)
38QR018C 38QR024C,030C,036C 38QR048C,060C
.433 (11) .709 (18) .16 (4)
Fig. 8 — Outdoor Fan Mounting Positions
7

Table 2 — Electrical Data
OUTDOOR
UNIT 38QR V-PH-HZ OPERATIONAL
VOLTAGE* COMPR FAN
FLA MCA MAX FUSE†
OR HACR TYPE
CKT BKR AMPS
Max Min LRA RLA
018C
208/230-1-60 253 187
49.0 8.9 .70 11.8 20
024C 61.0 10.9 .70 14.3 25
030C 76.0 13.5 .70 17.6 30
036C 90.5 17.9 .70 23.1 40
048C 110.0 22.4 1.45 29.5 50
060C 135.0 27.6 1.50 36.0 60
036C 208/230-3-60 253 187 66.0 11.2 1.45 15.5 20
048C 92.0 14.7 1.45 19.8 40
060C 105.0 17.7 1.50 23.6 45
036C 460-3-60 506 414 35.0 5.8 .80 8.1 15
048C 46.0 6.7 .80 9.2 15
060C 55.0 10.4 .83 13.8 20
LEGEND
FLA — Full Load Amps
HACR — Heating, Air Conditioning, Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps per NEC Section 430-24
NEC — National Electrical Code
RLA — Rated Load Amps (Compressor)
*Permissible limits of the voltage range at which unit will operate sat-
isfactorily.
†Time-delay fuse.
NOTES:
1. Control circuit is 24 v on all units and requires an external power
source.
2. All motors and compressors contain internal overload protection.
3. In compliance with NEC requirements for multimotor and combi-
nation load equipment (refer to NEC Articles 430 and 440), the
overcurrent protective device for the unit shall be fuse or HACR
breaker.
4. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the % voltage imbalance.
% Voltage Imbalance
= 100 x max voltage deviation from average voltage
average voltage
Filter Drier — Whenever the moisture liquid indicator
shows presence of moisture, replace the filter drier. Refer to
Carrier Standard Service Techniques Manual, Chapter 1, Re-
frigerants, for details on servicing filter driers.
High-Pressure Switch — This switch, located on dis-
charge line, protects against high discharge pressures caused
by such events as overcharge, outdoor-fan motor failure, sys-
tem restriction, etc. It opens on pressure rise at about
426 psi. If system pressures go above this setting during ab-
normal conditions, the switch opens.
DO NOT attempt to simulate the system abnormalities
— high pressures pose a serious safety hazard.
High-pressure switch is also checked with an ohmmeter
similar to checking low-pressure switch. If system pressure
is below 426 psi, switch shows continuity.
Low-Pressure Switch — This switch, mounted on
the suction line, has fixed, non-adjustable settings. The switch
is bypassed during defrost, and also for the first 2 minutes of
heating operation after defrost, by means of a time-delay
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v 452 + 464 + 455
Average Voltage = 3
1371
= = 457
3
Determine maximum deviation from average voltage.
(AB) 457 – 452=5v
(BC) 464 – 457=7v
(AC) 457 – 455=2v
Maximum deviation is 7 v.
Determine % voltage imbalance.
% Voltage Imbalance = 100 x 7= 1.53%
457
Thisamount ofphase imbalanceis satisfactoryas itis belowthe maxi-
mum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance
is more than 2%, contact your local electric utility com-
pany immediately.
relay. This prevents nuisance tripping of the low-pressure
switch.
To check pressure switch, attach pressure gage to suction
service valve gage port. Slowly close liquid shutoff valve
and allow compressor to pump down. Do not allow com-
pressor to pump down below 2 psig. Compressor should shut
down when suction pressure drops to cutout pressure in
Table 1, and should restart when pressure builds up to cut-in
pressure shown after CLO (compressor lockout switch) has
been reset and accessory Time Guard® device has com-
pleted its timing cycle.
Crankcase Heater — Heater prevents refrigerant mi-
gration and compressor oil dilution during shutdown when
compressor is not operating. If crankcase heater is deener-
gized for more than 6 hours, both compressor service valves
must be closed.
Crankcase heaters come in 2 basic types: wraparound (bel-
lyband) type that is wrapped externally around compressor
shell, and insertion type that is inserted into compressor oil
well in shell of compressor.
Crankcase heater is powered by high-voltage power of unit.
It is connected across the line side of the contactor and op-
erates continually. Use extreme caution when troubleshoot-
ing this device with power on.
8

To troubleshoot:
1. Apply voltmeter across crankcase heater leads to see if
heater voltage is on. Do not touch heater. Carefully feel
area around crankcase heater; if warm, crankcase heater
is probably functioning.
2. With power off and heater leads disconnected, check across
leads with ohmmeter. Do not look for a specific resis-
tance reading. Check for resistance or an open circuit, and
change heater if an open circuit is detected.
ServiceValves— The service valves in the outdoor unit
come from the factory frontseated. This means the refrig-
erant charge is isolated from the line set connection ports.
To prevent damage to the valve, use a wet cloth or other
accepted heat sink material on the valve before brazing.
The service valves must be backseated (turned counter-
clockwise until seated) before the service port caps can be
removed and the hoses of gage manifold connected. In this
position, refrigerant has access from and through outdoor and
indoor unit. The service valve cannot be field repaired, there-
fore, only a complete valve or valve stem seal and service
port caps are available for replacement.
AccuRater® Control (Bypass Type) — See
Fig. 4 for bypass-type AccuRater device components. The
piston has a refrigerant metering hole through it. The re-
tainer forms a stop for the piston in the refrigerant bypass
mode, and a sealing surface for liquid line flare connection.
To check, clean or replace piston:
1. Shut off power to unit.
2. Pump down unit using Pumpdown Procedure section on
page 7.
3. Remove liquid line flare connection from the AccuRater
device.
4. Pull retainer out of body, being careful not to scratch flare
sealing surface. If retainer does not pull out easily, care-
fully use locking pliers to remove retainer.
5. Slide piston out by inserting a small, soft wire, with small
kinks, through metering hole. Ensure metering hole, seal-
ing surface around piston cones, and fluted portion of pis-
ton are not damaged.
6. Clean piston refrigerant metering hole.
7. Replace retainer O-ring before reassembling AccuRater
control (Carrier O-ring part no. 99CC501052).
Defrost Control — The control, which consists of de-
frost control board and defrost thermostat, interrupts the nor-
mal system heating operation to defrost the outdoor coil, if
the coil saturated suction temperature indicates freezing
temperatures.
Defrost control board can be field set to check need for
defrost every 30, 50, or 90 minutes of operating time, by
connecting the jumper (labeled W1, on the circuit board) to
the spade terminal for the defrost time desired. The board is
factory set for 90 minutes. The defrost period is field select-
able, depending upon geographic areas and defrost de-
mands. Control board has additional feature that allows unit
to restart in defrost cycle if room thermostat is satisfied dur-
ing defrost.
Defrost control simultaneously tops outdoor fan, ener-
gizes reversing valve solenoid to return system to cooling
cycle (outdoor unit as condenser, indoor unit as evaporator),
and activates accessory electric heater.
The defrost timer limits defrosting period to 10 minutes.
Normally, the frost is removed and the defrost thermostat
contacts open to terminate defrosting before 10 minutes have
elapsed.
When defrosting is terminated, the outdoor-fan motor is
energized, and reversing valve solenoid is deenergized, re-
turning unit to heating cycle.
Reversing Valve — In heat pumps, changeover be-
tween heating and cooling modes is accomplished with a valve
that reverses flow of refrigerant in system. The reversing valve
solenoid can be checked with power off using an ohmmeter.
Check for continuity and shorting to ground. With control
circuit (24v) power on, check for correct voltage at solenoid
coil, and for burned or overheated solenoid.
With unit operating, other items can be checked, such as
frost or condensate on refrigerant lines.
Using a remote measuring device, check inlet and outlet
line temperatures. Do not touch lines. If reversing valve is
operating normally, inlet and outlet temperatures on appro-
priate lines should be similar.Any temperature difference would
be due to heat loss or gain across valve body. Temperatures
are best checked with a remote reading electronic-type ther-
mometer with multiple probes.
Figures 9 and 10 show test points on reversing valve for
recording temperatures. Insulate points for more accurate read-
ing. If valve is defective:
LEGEND
TP—Test Point
Fig. 9 — Reversing Valve (Cooling Mode or Defrost
Mode, Solenoid Energized)
LEGEND
TP—Test Point
Fig. 10 — Reversing Valve (Heating Mode,
Solenoid Deenergized)
9

1. Shut off all power to unit.
2. Remove all charge from system.
3. Remove valve using a tubing cutter.
4. Install new valve (wrap valve with a wet rag to prevent
overheating while brazing).
5. After valve is brazed in, check for leaks.
6. Evacuate and charge system. Operate system in both modes
several times to be sure valve functions properly.
Discharge Temperature Switch (DTS) — Switch,
used only on unit sizes 030 and 036 with scroll compressors,
senses high discharge temperature levels reached under ex-
treme operating conditions (low charge or low evaporator
airflow). Approximate cut-in and cutout temperatures are
290 F and 140 F, respectively.
Thermistors — The outdoor coil temperature ther-
mistor and outdoor air temperature thermistor are used only
with duct-free split systems that use a microprocessor con-
trol. Refer to separate installation instructions for models 40QA
and 40QY indoor units.
Time-Delay Relay (TDR1) — Relay, used only on
unit sizes 030 and 036 with scroll compressors, ensures that
compressor comes to complete stop before restarting.
Time-Delay (TDR2) — Relay prevents nuisance trip-
ping of low-pressure switch during system switchover after
defrost.
Compressor Lockout Switch — Units with com-
pressor lockout protective device shut down on any safety
trip. Determine reason for safety trip. To restart, turn the ther-
mostat to OFF position and then to COOL position.
Refrigerant Charging
To prevent personal injury, wear safety glasses and gloves
when handling refrigerant. Do not overcharge system
— this can cause compressor flooding.
Service valves must be fully backseated to close service
port. There is no Schrader valve at the service port, and
failure to backseat the valve could result in loss of sys-
tem charge or personal injury.
NOTE: Do not vent or depressurize unit refrigerant to at-
mosphere. Remove and reclaim refrigerant following ac-
cepted practices.
To check and adjust charge during cooling season, use
Tables 3 and 4 and the following procedure:
1. Operate unit a minimum of 15 minutes before checking
charge.
2. Measure suction pressure by attaching a gage to suction
valve service port.
3. Measure suction line temperature by attaching a service
thermometer to unit suction line near suction valve. In-
sulate thermometer for accurate readings.
4. Measure outdoor coil inlet-air dry bulb temperature with
a second thermometer.
5. Measure indoor coil inlet-air wet bulb temperature with
a sling psychrometer.
6. Refer to Table 3. Find air temperature entering outdoor
coil and wet-bulb temperature entering indoor coil. At
this intersection, note the superheat temperature.
7. Refer to Table 4. Find superheat temperature and suc-
tion pressure, and note suction line temperature. If unit
has higher suction line temperature than charted tem-
perature, add refrigerant until charted temperature is
reached.
8. If unit has lower suction line temperature than charted
temperature, remove and reclaim refrigerant until charted
temperature is reached.
9. If air temperature entering outdoor coil or pressure at
suction valve changes, charge to new suction line tem-
perature indicated on chart.
10. This procedure is independent of indoor air quality.
HeatingMode — To check system operation during heat-
ing cycle, use Table 5. This table indicates whether a correct
relationship exists between system operating pressure and
air temperatures entering indoor and outdoor units. In
heating mode, check should be made approximately 15 min-
utes after defrost with unit running with a clean coil.
Table 3 — Superheat Charging Table
(Superheat Entering Suction Service Valve)
OUTDOOR
TEMP INDOOR COIL ENTERING AIR (F) WB
50 52 54 56 58 60 62 64 66 68 70 72 74 76
55 9 12141720232629323537404245
60 7 10121518212427303335384043
65 * 6 10 13 16 19 21 24 27 30 33 36 38 41
70 * * 71013161921242730333639
75 * * * 6 9 12 15 18 21 24 28 31 34 37
80 ****581215182125283135
85 ******811151922263033
90 ******59131620242731
95 *******6101418222529
100 ********81215202327
105 ********5913172226
110 *********611152025
115 **********8141823
LEGEND
WB — Wet Bulb
*Do not attempt to charge system under these conditions or refrig-
erant slugging may occur.
Table 4 — Required Suction-Tube Temperature (F)
(Entering Suction Service Valve)
SUPERHEAT
TEMP (F) SUCTION PRESSURE AT SERVICE PORT (psig)
61.5 64.2 67.1 70.0 73.0 76.0 79.2 82.4 85.7
035 37 39 41 43 45 47 49 51
237 39 41 43 45 47 49 51 53
439 41 43 45 47 49 51 53 55
641 43 45 47 49 51 53 55 57
843 45 47 49 51 53 55 57 59
10 45 47 49 51 53 55 57 59 61
12 47 49 51 53 55 57 59 61 63
14 49 51 53 55 57 59 61 63 65
16 51 53 55 57 59 61 63 65 67
18 53 55 57 59 61 63 65 67 69
20 55 57 59 61 63 65 67 69 71
22 57 59 61 63 65 67 69 71 73
24 59 61 63 65 67 69 71 73 75
26 61 63 65 67 69 71 73 75 77
28 63 65 67 69 71 73 75 77 79
30 65 67 69 71 73 75 77 79 81
32 67 69 71 73 75 77 79 81 83
34 69 71 73 75 77 79 81 83 85
36 71 73 75 77 79 81 83 85 87
38 73 75 77 79 81 83 85 87 89
40 75 77 79 81 83 85 87 89 91
10

If pressure and temperature do not match on chart, system
refrigerant charge may not be correct or other system ab-
normalities may exist. Do not use table to adjust refrigerant
charge.
When recharging is necessary during heating season, weigh
in total charge as indicated in separate indoor unit installa-
tion instructions. Remove any refrigerant remaining in sys-
tem before recharging. If the system has lost complete charge,
evacuate and recharge by weight. Service port connections
are provided on liquid and suction line service valves. For
evacuation and recharging, Dial-a-Charge charging cylin-
der, or similar device, is an accurate device for recharging
systems by weight.
MAINTENANCE
Before performing recommended maintenance, be sure
unit main power switch is turned off. Failure to do so
may result in electric shock or injury from rotating fan
blade.
Lubrication
COMPRESSOR — Compressor contains factory oil charge;
replace oil when lost. See Table 1 for oil recharge and refer
to Carrier Standard Service Techniques Manual, Chapter 1,
page 1-21, for oil recharging procedure. Use Carrier PP33-1,
Texaco WF-32 or Suniso 3GS oil.
FAN-MOTOR BEARINGS — Oiling holes are provided at
each end of condenser fan motor. Remove fan motor and
lubricate motor with 32 drops (16 drops per hole) of SAE-10
nondetergent oil at intervals described below:
• Annually, when environment is very dirty, ambient tem-
perature is higher than 105 F, and average unit operating
time exceeds 15 hours a day, or
• Every 3 years when environment is reasonably clean, am-
bient temperature is less than 105 F, and unit operating
time averages 8 to 15 hours a day, or
• Every 5 years when environment is clean, ambient tem-
perature is less than 105 F, and unit operating time aver-
ages less than 8 hours a day.
Cleaning
CLEANING COILS —
Coils should be washed out with water, or blown out with
compressed air. Note that the blow-thru design causes dirt
and debris to build up on the inside of the coils.
Clean coil annually or as required by location or outdoor
air conditions. Inspect coil monthly, and clean as required.
Fins are not continuous through coil sections. Dirt and de-
bris may pass through first section, become trapped between
the row of fins and restrict condenser airflow. Use a flash-
light to determine if dirt or debris has collected between coil
sections. Clean coil as follows:
1. Turn off unit power.
2. Using a garden hose, or other suitable equipment, flush
coil from the outside to remove dirt. Be sure to flush all
dirt and debris from drain holes in base of unit. Fan mo-
tors are waterproof.
Table 5 — Heating Operation Pressure Table, Fixed Restrictor (High Pressure at Suction Valve, Low Pressure
at Liquid Valve, Suction Pressure at Compressor)
UNIT
38QR
INDOOR
DRY
BULB
TEMP (F)
OUTDOOR TEMPERATURE (F) DRY BULB UNIT
38QR
INDOOR
DRY
BULB
TEMP (F)
OUTDOOR TEMPERATURE (F) DRY BULB
60 50 40 30 20 10 0 60 50 40 30 20 10 0
018C
60 HIGH 219.8 199.2 181.4 166.0 152.5 139.7 128.4
036C
60 HIGH 226.0 205.4 188.0 172.9 160.0 148.4 137.4 LOW 83.8 71.0 59.3 48.5 38.8 30.2 22.8 LOW 76.1 64.7 54.3 44.7 36.1 28.2 21.2
SUCTION 68.8 58.6 49.3 40.7 32.9 26.0 19.8 SUCTION 61.9 52.6 44.1 36.3 29.3 22.8 17.0
70 HIGH 247.7 225.6 206.4 189.5 173.5 159.4 146.5 70 HIGH 254.7 233.0 214.4 198.2 183.9 169.7 158.3 LOW 85.1 72.1 60.0 49.1 39.3 30.1 23.4 LOW 77.3 65.8 55.3 45.5 36.6 28.8 21.8
SUCTION 70.4 60.0 50.5 41.8 33.9 26.9 20.6 SUCTION 63.3 54.0 45.3 37.4 30.1 23.5 17.7
80 HIGH 278.3 254.3 233.5 214.0 196.2 180.3 165.5 80 HIGH 286.7 263.5 243.3 225.5 207.7 193.5 180.4 LOW 86.5 73.0 60.7 49.7 40.0 31.5 24.0 LOW 78.9 67.1 56.2 46.2 37.3 29.5 22.5
SUCTION 72.0 61.4 51.7 42.8 34.8 27.7 21.4 SUCTION 65.0 55.4 46.6 38.4 31.0 24.4 18.4
024C
60 HIGH 234.1 210.3 190.4 173.6 159.4 147.3 136.2
048C
60 HIGH 231.6 210.2 191.8 175.4 162.1 148.7 137.6 LOW 77.9 66.2 55.4 45.5 36.5 28.5 21.2 LOW 80.4 68.2 56.9 46.5 37.2 29.0 21.7
SUCTION 66.3 56.4 47.3 38.9 31.3 24.4 18.2 SUCTION 67.8 57.6 48.1 39.4 31.5 24.5 18.2
70 HIGH 262.0 237.0 215.8 197.8 182.5 168.9 156.3 70 HIGH 261.2 238.3 218.5 201.2 184.3 170.2 157.8 LOW 79.4 67.4 56.4 46.3 37.0 28.8 21.6 LOW 81.8 69.3 57.7 47.1 37.7 29.6 22.2
SUCTION 68.0 57.9 48.6 40.0 32.2 25.2 18.9 SUCTION 69.4 58.8 49.1 40.3 32.3 25.2 18.8
80 HIGH 292.6 265.9 243.3 224.2 207.4 191.3 178.0 80 HIGH 293.2 268.6 247.2 226.7 208.6 193.1 178.9 LOW 80.9 68.6 57.3 47.0 37.6 29.4 22.2 LOW 83.2 70.3 58.5 47.8 37.8 30.2 22.8
SUCTION 69.8 59.4 49.8 41.0 33.1 25.9 19.6 SUCTION 70.9 60.1 50.2 41.2 33.1 25.9 19.4
030C
60 HIGH 222.3 202.2 185.1 170.4 157.9 146.7 135.9
060C
60 HIGH 228.9 207.5 189.6 173.8 160.4 147.6 136.6 LOW 83.8 71.4 60.0 49.3 39.7 30.9 23.3 LOW 85.9 72.7 60.9 50.0 40.1 31.3 23.5
SUCTION 61.8 52.6 44.1 36.2 29.0 22.5 16.7 SUCTION 63.6 53.9 44.9 36.8 29.4 22.7 16.8
70 HIGH 250.9 229.6 211.2 195.4 181.6 167.8 156.6 70 HIGH 258.3 235.7 215.9 199.0 183.4 168.8 156.4 LOW 85.2 72.5 60.7 49.9 40.1 31.3 23.7 LOW 86.9 73.8 61.6 50.5 40.5 31.7 24.0
SUCTION 63.5 54.0 45.3 37.2 29.9 23.2 17.3 SUCTION 65.1 55.2 46.0 37.7 30.2 23.5 17.5
80 HIGH 282.2 259.3 239.5 222.6 205.6 191.3 178.5 80 HIGH 290.0 265.7 244.4 225.5 206.7 191.3 177.2 LOW 86.6 73.5 61.5 50.4 40.6 31.9 24.3 LOW 88.4 74.7 62.3 50.9 41.1 32.3 24.5
SUCTION 65.1 55.4 46.4 38.2 30.7 24.0 18.0 SUCTION 66.5 56.5 47.2 38.7 31.1 24.3 18.2
11

TROUBLESHOOTING CHART — HEATING CYCLE
LEGEND
NC — Normally Closed
ODT — Outdoor Thermostat
NOTE: For systems with indoor units equipped with microprocessor
control, see separate controls, service, and troubleshooting manual.
12

TROUBLESHOOTING CHART — COOLING CYCLE
LEGEND
NC — Normally Closed
NOTE: For systems with indoor units equipped with microprocessor
control, see separate controls, service, and troubleshooting manual.
13

Copyright 1992 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 5a 5a PC 111 Catalog No. 563-882 Printed in U.S.A. Form 38QRC-1SI Pg 16 3-92 Replaces: New