This Service Manual enables a service technician to
.service and repair a family of similar condensing units
and heat pumps. Outwardly, many models appear
tC.O.P. — Coefficient of Performance (heating), determined by dividing
DIAMETERS
(in.)
22
22
30
30
17
17
22
30
30
Btu output by power input required to producethis Btu output.
SEER*
(Nominal)
■ 9.0
9.0
9.0
9.02.85
9.0
9.0
9.0
9.02.85
8.0
8.0
8.0
8.02.55
8.0
8.0
8.0
8.0
10.0
10.0
10.0
10.0
10.02.85
10.0
10.02.85
CiO.P.t
(Minimum)
2.85
2.85
2.85
2.85
2.85
2.85
2.55
2.55
2.55
2.55
2.55
2.55
2.55
2.85
2.85
2.85
2.85
2.85
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book |l1 |4 |4
Tab jsa
5a|2a|5a
PC 101
Catalog No. 563-857 Printed in U.S.A. Form 38E.Q-1SM
For replacement items use Carrier Specified Parts.
Pgi
11-85
Replaces; New
Factory-Installed Options — Any condensing unit
or heat pump listed in Tables 1 and 2 may be ordered as
Basic or in one of 3 factory-option packages. Package
designations are included in model number (excluding
Table 3 — Option Packages
Basic). Example: 38EN0243015A/. SM designates this
unit as sheet metal option package. Option package
designations are shown in Table 3.
Basic
Sheet Metal Option (SM)
Deluxe Option (DL)
Custom Deluxe Option (CD)Same unit as (DL) except for addition of
Basic
Sheet Metal Option (SM)
38EH,ES
Standard unit with no added options.
Same unit as Basic except with addition
of louvered inlet casing.
Same unit as (SM) except for addition ■
of start assist components on single
phase units, crankcase heater, highand low-pressure switches, and
accumulator.
sound shield around compressor, and
Time Guard II device.
38EN
Standard unit with no added options.
Same unit as Basic except for addition
’Factory refrigerant charge is adequate when indoor unit and outdoor unit are the same size
and are connected with 25 ft or less of field tubing of recommended size or Carrier accessory
tubing. For tubing requirements beyond 50ft, consult Carrier distributor.
H-R
NOTE: Originally an extended voltage compressor.
Select replacement compressor for voltage required:
tPF5366HD (200-3-60), PG5366HD (230-3-60).
tPF6766HF (200-3-60), PG6766HF (230-3-60).
Table 5 — Heat Pump Specifications
OUTDOOR
UNIT
MODEL NO.
38QH
015
018
024
030
036
042 .
048
060
060341
030
036
042
048
060
036
042
048
060
ON
015
018
024
030
036
042
048
060
036
042
048
060
036
042
048
060
QS
018
024
030
036
042
'Factory refrigerant charge is adequate when indoor unit and outdoor unit are the same
size and are connected with 25ft or less of field tubing of recommended size orCarrier
accessory tubing. For tubing requirements beyond 50ft, consult Carrier distributor.
NOTE: Originally an extended voltage compressor.
Select replacement compressor forvoltage-required:
tPF5366HD (200-3-60), PG5366HD (230-3-60).
Recharge
37
52
74
50
507.9
50
7414.1
50
50
74
20
28
445.6
446.1 . ,
448.9
509.5
72
72
448.9
50
72
72
448.9
72
72
72
28
46
46
46
51
REFRIG
CHARGE*
(R-22)
5.3
5.5
7.8
7.8
7.9
11.0
12.5
14.1
14.0
7.8
11.0
12.5
7.9
11.0
12.5
14.1
3.6
4.1
9.7
10.8
9.5
9.7
10.8
9.5
9.7
10.8
6.8
7.5
8.5
10.6
11.5
SAFETY CONSIDERATIONS
Service and repair of these units should be attempted
only by trained service technicians familiar with Carrier
Standard Service Instructions.
All equipment should be installed in accordance with
accepted practices and in compliance with all national
and local codes.
Power should be turned off when servicing or repair
ing electrical components. Extreme caution should be
observed when troubleshooting electrical components
with power on. Observe all warning notices posted on
equipment.
Refrigeration system contains refrigerant under
pressure. Extreme caution should be observed when
handling refrigerants. Wear safety glasses and gloves to
prevent personal injury. During normal system opera
tion, some components are hot and can cause burns.
Rotating fan blades can cause personal injury. Appro
priate safety considerations are posted throughout this
manual where potentially dangerous techniques are
addressed.
SERVICE
Cabinet — Certain maintenance routines and repairs
require removal of cabinet panels. All condensing units
and heat pump models of this series have same basic
design with only minor differences. See Fig. 1.
REMOVING LOUVERED CASING — (See Fig. 2.)
1. Turn off all power to unit.
2. Loosen screws around circumference of fan orifice.
3. Remove screws around circumference of basepan.
4. Remove screws along control box support brackets.
5. Carefully remove louvered casing.
A CAUTION
Do not attempt to remove wire grille around coil.
Grille is integral part of coil structure and sup
ports coil.
REMOVING FAN ORIFICE — (See Fig. 3.)
1. Turn off all power to unit.
2. Remove screws holding grille on top of fan orifice.
3. Unplug wires from fan motor. Fan blades on certain
models may have to be removed. Refer to Service —
Electrical.
4. Remove screws holding fan orifice to wire grille and
control box.
5. Remove fan orifice.
ELECTRICAL BOX ACCESS — (See Fig. 1.)
1. Turn off all power to unit.
2. Remove screws holding box cover.
DISCHARGE
GRILLE
BASIC CONDENSING UNIT
r-6" AIRFLOW AND
SERVICE CLEARANCE
ON 3 SIDES — 12" ON
REMAINING SIDE
ON 3 SIDES — 12" ON
REMAINING SIDE
LOUVERED CONDENSING UNIT
DISCHARGE
GRILLE
IVb" DIAM
HOLE
WITH 1%"
CONCENTRIC
KNOCKOUT
FOR POWER
WIRING
(OPP. SIDE)
ELEC. WIRING RACEWAY
LIQUID LINE
SERVICE PORT
ATSERVlOE
VALVE(CLG
CYCLE)
SUCTION
SERVICE PORT
AT SERVICE
VALVE(CLG
CYCLE)
SUCTION
SERVICE PORT
(HIDDEN)
COIL
SUPPORT
r-6" AIRFLOW AND
SERVICE CLEARANCE
ON 3 SIDES — 12" ON
REMAINING SIDE
DISCHARGE
GRILLE
LIQUID LINE
SERVICE PORT
AT SERVICEVALVE (CLG
CYCLE)
SUCTION
SERVICE POR
AT SERVICE
VALVE(CLG
CYCLE)
SUCTION
SERVICE PORT
(HIDDEN)
4'-0” OVERHEAD SPACE REQUIRED
FOR SERVICE AND AIRFLOW
r-6" AIRFLOW AND
SERVICE CLEARANCE
ON 3 SIDES —12" ON
REMAINING SIDE
BASIC HEAT PUMP UNIT
Fig. 1 — Condensing and Heat Pump Units
LOUVERED HEAT PUMP UNIT
SCREWS
TOP COVER
BASEPAN FLANGE
C
Fig. 2 — Louvered Casing Assembly
Fig. 3 — Removing Orifice Fan
Electrical — Exercise extreme caution when work
ing on any electrical components. Shut off all power
to system prior to troubleshooting. Some trouble
shooting techniques require power to remain on. In
these instances, exercise extreme caution to avoid
danger of electrical shock. ONLY TRAINED SERVICE
PERSONNEL SHOULD PERFORM ELECTRICAL
TROUBLESHOOTING.
CONTACTORS — (See Fig. 4.) Contactor provides
means of applying power to unit using lower power
(24 v) from transformer in order to power the contactor
coil. Depending on unit model, you may encounter
single-, double- or triple-pole contactors to break power.
One side of the line may be electrically hot, so extreme
caution must be exercised when troubleshooting.
The contactor coil for these and most residential
models of condensing units and heat pumps is powered by
24 vac. If contactor does not operate:
1. With power off, check whether contacts are free to
move. Check for severe burning or arcing on contact
points.
ATTACHING CASING TO TOP COVER
AND BASEPAN
2. With power off, use ohmmeter to check for continuity
of coil. Disconnect leads before checking. A lowresistance reading is normal. Do not look for a specific
value as different part numbers used will have different
resistance values.
3. Reconnect leads and apply low-voltage power to
contactor coil. This may be done by leaving highvoltage power to outdoor unit off, and by turning
thermostat to heat or cool. Check voltage at coil with
voltmeter. Reading should be between 20 - 30 volts.
Contactor should pull in if voltage is correct and coil
is good. If contactor does not pull in, change
contactor.
4. With high-voltage power off and contacts pulled in,
check for continuity across contacts with ohmmeter.
A very low or zero resistance should be read. Higher
readings could indicate burned or pitted contacts
which may cause future failures.
Fig. 4 — Contactor
CAPACITORS — (See Fig. 5.)
A CAUTION
Capacitors can store electrical energy when power
is off. Electrical shock can result if you touch the
capacitor terminals and discharge this stored energy.
Exercise extreme caution when working near
capacitors. With power off, discharge stored energy
by shorting across the capacitor terminals with a
15,000-ohm, 2-watt resistor, or a screwdriver blade
with insulated handle.
Hard-Start Capacitors and PTC Devices — Sometimes,
under adverse conditions, a standard run capacitor in a
system is inadequate to start compressor. In these
instances, a start-assist device is used to provide an extra
starting boost to compressor motor. The first device is
called a PTC (positive temperature coefficient) or ther
mistor (see Fig. 6). It is a resistor wired in parallel with run
capacitor. As current flows through it at start-up, it heats
up. As it heats up, its resistance increases greatly, until
it effectively lowers current through it to an extremely
low value. This, in effect, removes it from the circuit.
After system shuts down, resistor cools and resistance
value returns to normal, until next time system starts.
Thermistor device is adequate for most conditions,
however, in systems where off cycle is short, device
cannot cool fully and becomes less effective as a start
device. It is an easy device to troubleshoot. Turn off all
power to system.
Check thermistor with ohmmeter as described below.
If indoor coil does not have a bleed-type expansion
device, it may be necessary to remove start thermistor
and replace with accessory start capacitor and relay.
Shut off all power to unit. Remove PTC from unit.
Wait at least 10 minutes for PTC to cool to ambient
temperature.
RUN CAPACITOR START CAPACITOR
Fig. 5 — Capacitors
Capacitors are used as a phase shifting device to aid in
starting certain single-phase motors. Check capacitors
as follows:
1. Always check capacitors with power off. Attempting
to troubleshoot a capacitor with power on can be
dangerous. Defective capacitors may explode when
power is applied. Insulating fluid inside is combustible
and may ignite, causing burns. After power is off,
discharge capacitors as outlined above. Disconnect
capacitor from circuit. Use ohmmeter, check each
terminal to ground (use capacitor case). Discard any
capacitor that shows resistance. Place ohmmeter leads
across capacitor and place on R x 10k scale. Meter
should jump to a low resistance value and slowly climb
to higher value. Eailure of meter to do this indicates
an open capacitor. If resistance stays at zero or a low
value, capacitor is shorted.
2. Capacitance testers are available which will read value
of capacitor. If value is not within ± 10% value stated
on capacitor, it should be changed. If capacitor is
not open or shorted, its capacitance value is calcu
lated by measuring voltage across capacitor and
current it draws.
A WARNING
Exercise extreme caution when taking readings
while power is on. Use following formula to
calculate capacitance:
^ . , r,.2650 X amps
Capacitance (mfd) =
3. Remove any capacitor that shows signs of bulging,
dents or leaking. Do not apply power to a defective
capacitor as it may explode.
volts
Measure resistance of PTC with ohmmeter. Resistance
of 25-ohm PTC is measured between center tab and
end tab with jumper across 2 end terminals.
Fig. 6 — PTC Devices
The cold resistance (Rj) of any PTC device should be
If PTC resistance is appreciably lower or more than
200% higher than rating, device is defective.
If thermistor is good and compressor does not start,
disconnect thermistor from starting circuit. Give com
pressor a temporary capacitance boost. Run compressor
for 10 minutes, shut off, allow system pressure to equal
ize. Reconnect start thermistor. Try restarting com
pressor without boost capacitor. If after 2 attempts,
compressor does not start, remove thermistor. Add an
accessory start capacitor relay package.
Temporary Capacitance Boost — (See Fig. 7.) There are
times when a temporary capacitance boost is needed to
get compressor started. Do not under any circumstances
attach temporary boost capacitor directly across com
pressor terminals. Serious personal injury can result.
Exercise extreme caution with this procedure when highvoltage power is on. If compressor motor does not start,
it may be due to low-line voltage, improper pressure
equalization or weak run capacitor. Check each possi
bility, attempt capacitance boosting before adding
auxiliary start capacitor and relay.
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