Page 1
iNjumber One
AirConditbning
Maker
Division of
Carrier Corporation
Heat Pump — Outdoor Section
INDEX
Page
INSTALLATION................................................ 1-7
Step 1 — Check Equipment and Jobsite . 1
• UNPACKAGE UNIT
• INSPECT EQUIPMENT
• COMPLETE OR CONSIDER SYSTEM
REQUIREMENTS
Step 2 — Mount Outdoor Heat Pump .. 3
• ON THE GROUND: MOUNT UNIT
ON A SOLID, LEVEL CONCRETE
PAD
• ON THE ROOF: MOUNT UNIT ON
A LEVEL PLATFORM OR FRAME
Step 3 — Make Piping Connections
_______
3-5
• REPLACE THE ACCURATER™ RE
FRIGERANT CONTROL PISTON IN
THE INDOOR COIL AS REQUIRED
• CONNECT REFRIGERANT LINES
Step 4 — Make Electrical Connections .. 5-7
• INSTALL A BRANCH CIRCUIT
DISCONNECT PER NEC
• ROUTE LINE POWER LEADS
INTO UNIT
• CONNECT GROUND LEAD AND
POWER WIRING
• SEE INDOOR UNIT AND ELECTRIC
HEATER INSTALLATION, START-UP
AND SERVICE INSTRUCTIONS
• CONNECT CONTROL POWER
WIRING (24 v)
START-UP............................................................ 7
SERVICE............................................................ 7-14
MAINTENANCE................................................ 14-17
SAFETY CONSIDERATIONS
Installation and servicing of air conditioning
equipment can be hazardous due to system pres
sure and electrical components. Only trained and
qualified service personnel should install, repair or
service air conditioning equipment.
Untrained personnel can perform basic main
tenance functions of cleaning coils and cleaning
and replacing filters. All other operations should be
performed by trained service personnel. When
working on air conditioning equipment, observe
precautions in the literature, tags and labels attached
to the unit and other safety precautions that may
apply.
Follow all safety codes. Wear safety glasses and
work gloves. Use quenching cloth for brazing oper
ations. Have fire extinguisher available for all
brazing operations.
WARNING: Before performing sersice or
maintenance operations on system, turn off
mam power switches to indoor unit and out
door unit. Turn off accessory heater power
switch if applicable. Electrical shock could cause
personal injury'.
INSTALLATION
Step 1 — Check Equipment and Jobsite
UNPACKAGE UNIT — Move to final location.
Lift carton off, taking special care not to damage
service valves or grilles.
INSPECT EQUIPMENT — File claim with ship
ping company if shipment is damaged or incomplete.
COMPLETE OR CONSIDER SYSTEM RE
QUIREMENTS before installing the 38QB:
Consult local building codes and National
Electrical Code (NEC) for special installation
requirements.
When installing, allow sufficient space for
airflow clearance, wiring, refrigerant piping and
servicing. Position so water or ice from roof cannot
drop directly on top of unit.
Make provisions for condensate drainage and
defrost water disposal whether unit is installed on
ground or roof. (Ensure unit basepan drainage
holes are not blocked.) See Step 2 for details. Roof
installation method for 38QB depends on building
construction and special requirements of local
codes. Be sure that roof can support unit weight.
It is recommended that 38 QB units be used with
Carrier approved indoor sections; see Table 1.
System Refrigerant Control on 38QB units and
matching Carrier indoor units is a factory-installed
AccuRater™ device (bypass type). Bypass-type
AccuRater components are discussed in the service
section of this booklet. The AccuRater piston has a
refrigerant metering hole thru it and is field replace
able. Table 2 indicates indoor units for which the
Carrier Corporation 1982
Form 38QB-1SIM
Page 2
4'-0"(l220mm) OVERHEAD SPACE REQUIRED
FOR SERVICE AND AIRFLOW
^ (22 mm)
DIAM HOLE
FOR CONTROL
WIRING
LIQUID VALVE SERVICE PORT
AIRFLOW SUCTION SERVICE PORT
f
VAPOR VALVE SERVICE PORT
б" (152 mm)
THICK
l|"(35mm)
DIAM HOLE
FOR POWER
WIRING
l'-0"(305 mm)
GRAVEL APRON
I'-n" (584mm) DIAM
T
б" (I52 mm)
THICK
CONCRETE MOUNTING PAD FOR 38QB0I8
'MARKER TAPE
(HIDDEN)
r
12" (305mm)
GRAVEL APRON
I'-n" {585mm) DIAM x б"(152 mm)THK CONCRETE
MOUNTING PAD FOR 38QB0I8
2-6" (762 mm) DIAM x б" (152mm) THK CONCRETE
MOUNTING PAD FOR 38QB024-042
Fig. 1 — Dimensions, Connections and
Mounting Pad (Refer to Table 2)
2'-6"(762mm) DIAM
6" (152 mm
THICK
CONCRETE MOUNTING PAD FOR 38QB024-042
Fig. 2 — Accessory Mounting Rack
Table 1 — Carrier Approved 38QB Systems
OUTDOOR
UNIT
38QB
018
024 46
030
036 61
042
‘Replace factory-installed piston with this piston size
REQUIRED
OUTDOOR
PISTON
SIZE
42
59
63
INDOOR
UNIT
MODEL &
SIZE
28HQ,VQ024
40AQ024
40DQ024
28HQ.VQ030
40AQ030
40DQ030
28HQ,VQ036
40AQ036
40A0036
28HQ.VQ042
40QB042
40QB042
28HQ.VQ048
REQUIRED
INDOOR
PISTON
SIZE
52
61*
70*
70*
76
76*
Page 3
Table 2 — Installation Data (Fig. 1)
required replacement piston is factory supplied with
specified 38QB outdoor unit. Replace piston as
described under AccuRater™ Servicing on page 13.
Top Cover Removal — Top cover can be removed
for wiring or servicing heat pump. Loosen decora
tive strip and slide down off screw heads. Remove
3 screws in connector plate and 2 screws on front of
unit. Loosen remaining 4 screws. Lift top from unit
(See Fig. 1).
Step 2 — Mount Outdoor Heat Pump
ON THE GROUND: MOUNT ON A SOLID,
LEVEL CONCRETE PAD (See Fig. 1). Swing 3
legs down and lock in position, except when using
accessory rack. Use accessory heat pump rack
(Fig. 2) in areas where prolonged subfreezing tem
peratures or heavy snow occur. (Refer to installation
instructions included with rack.) Drainage holes in
unit base must not be obstructed.
ON THE ROOF: MOUNT UNIT ON A LEVEL
PLATFORM OR FRAME. Proper precaution
must be taken for support of unit in roof design.
Elevate unit for proper clearance as described under
ground installation above. Plan roof design and
water drainage to prevent unit from setting in water.
Flash all roof openings to prevent leaks.
Roof mounted units exposed to winds above
5 mph (8 km/ h) may require protective wind baffles
(field fabricated) to achieve adequate defrost.
Step 3 — Make Piping Connections — The
38QB can be connected to indoor units using
Carrier accessory tubing package or field-supplied
tubing of refrigerant grade. See Table 2 for unit
piping connection type and size. See Table 3 for
accessory tubing sizes. For requirements beyond
50 ft (15.2 m), obtain information from local Carrier
distributor. Isolate interconnecting tubing from
framing and ductwork or where tubing runs thru
stud spaces, enclosed ceilings or pipe chases. Use
isolation type hangers. Fig. 3, since rigid fastening
transmits pulsations to structure creating objec
tionable sound.
A capacity reduction will result if accessory tub
ing is used in 38QB042 systems. For example, when
a 25-ft (7.6 m) 7/8-in. (22 mm) accessory package is
used, there is a capacity reduction of 1-1/2 percent.
Page 4
Table 3 — Accessories
PART NO.
38CQ900081
38CQ900111
38QB90002106
38HQ9000011
28VQ900011
38RQ900081
38RQ900001
38HQ900002
38CQ900172
38RQ900091
38QB90000106
38QB90001106
38HQ90014106
38CQ900141
HC95DD121*
HC95DD058*
HC95DD088*
HN61HB515*
HN61HB496*
TUBING
PACKAGE
38LS958151
38LS958201 20
38LS958251 25 3/8
38LS958301
38LS958351
38LS958401
38LS958501
38LS934151 15 "IMd 3/8
38LS934201
38LS934251
38LS934301 30 3/8
38LS934351
38LS934401
38LS934501 50 3/8 3/8
38LS978151
38LS978201
38LS978251 25 3/8 3/8
38LS978301 30 3/8 3/8
38LS978351
38LS978401
38LS978501
•Available thru Carrier Service Parts
fSuction line is insuiated and has 90° bend
jpor 5/8-in (7.9-mm) evaporator connection, cut off 3/4-in. (19 05-mm) belled end
••Capacity reduction may occur when 7/8-in, (22 22-mm) accessory tubing is used on 38QB042
Length
(ft)
15
30
35
40
50
20
25
35
40
15
20
35 3/8
40 3/8
50 '^<2
Low-Voltage Control — Honeywell Thermostat HH07AT171 and
Thermostat Subbase HH93AZ173 — (Automatic Changeover)
Low-Voltage Control — Honeywell Thermostat HH07AT171 and
Thermostat Subbase HH93AZ175 — (Manual Changeover)
Service Sentry (Six HN65CT004)
Hot Shot® Domestic Water Preheater
Twelve 3/4- x 1-1/8 in. connection adapters
Bi-Flow Heat Pump Filter Drier (Six KH45LD077)
Supplemental Heat Relay — (Required with 2 outdoor thermostats.)
(Service Parts)
Outdoor Thermostat (Six 38HQ9000101)
Optimizer Control Outdoor Thermostat (Six 38CQ900161 ref HH22AG110)
Optimizer II Control Assembly (Use with HH22AG110 outdoor thermostat.)
Heat Pump Rack
Heat Pump Rack
Optimizer III (Six 38HQ900141)
Solid-State Time Guard It (24-volt)
Start Capacitor
Start Capacitor
Start Capacitor
Relay
Relay
Liquid
OD
(in.) (in.)
3/8 3/8
3/8
i ■ m
5/16
5/16 3/8;
5/16 3/8
1/4
ÍL
3/8 3/8
3/8
I'-^.5?
r m ".
3/8
? ' '■
3/8
Í
3/8 3/8
3/8
\
1
3/8
DESCRIPTION
Tube End OD
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
10
10
ri^’ 3/4
I
I ’
I 10
i ■ W
10
10 3/4
' Í0
10 7/8^
10
10
■ ^0
10 7/8*
(in.)
5/8
5/8
5/8
5/8
5/8
5/8
....
: 5/8
3/4
3/4
3/4
3/4
3/4
7/8^
7/8^
7/8^
7/8^
7/8*
OD
TUBING
n
45.7» I
ÍS79
ism
15.7»
mm
miss
ism I
ISiíSl
WM
Í0MI
15061
2a 22 I
22.a2i
2222
2ZZH i
22.22 S
i
Suctionf
MODEL 38QB
All
042
All
018
024, 030, 036, 042
All
018
024, 030
036
018
024, 030, 036
024, 030
036, 042
r
Unit
38QB
018
When other than 25 ft (7,6 m) of interconnecting
tubing is used, follow special requirements described
in Refrigerant Charging. Do not use less than 10 ft
(3 m) of interconnecting tubing. Do not cut 5/ 16-in.
(7.94 mm) or 1/4-in. (6.35 mm) liquid line due to
swage at ends. Do not cut 7/8-in. (22.22 mm)
suction line. Bend or coil to fit.
Do not use damaged or contaminated tubing.
Always evacuate or purge evaporator coil and
tubing system (use field-supplied refrigerant, not
unit refrigerant).
When making tubing connections, be sure to
provide clearance at unit for electrical connections.
Page 5
REPLACE THE ACCURATER™ REFRIG
ERANT CONTROL PISTON IN THE INDOOR
COIL AS REQUIRED before connecting refrig
erant lines. See Table 1. Correct piston is supplied
with 38QB unit. For piston replacement instruc
r
tions, see AccuRater Servicing on page 13.
Sweat Connection to Compatible Fitting (Use
refrigerant grade tubing.)
1. Remove locking nut, rubber O-ring and Schrader
core from valve.
2. Cut tubing to correct length.
3. Insert tube into Compatible Fitting. Wrap top
CONNECT REFRIGERANT LINES to fittings on
unit suction and liquid service valves (Fig. 1).
Liquid service valve has flare fitting; suction service
valve has Compatible Fitting. Make suction line
connection first. Slide flare nut on liquid line, then
flare and connect liquid line. Use a maximum
torque of 15ft-lb (20N/m) to tighten flare nut.
(Do not disassemble AccuRater.) Unit Compatible
Fitting permits mechanical or sweat connection as
described below.
When a 7/8-in. (22.22 mm) field-supplied suction
line is used on 38QB036, a field-supplied 3/4-in.
(19.05 mm) to 7/8-in. (22.22 mm) suction line
and bottom of service valves in wet cloth to pre
vent damage by heat. Solder with low tempera
ture ([430 F] [221 C]) silver alloy solder.
4. Replace Schrader core.
5. Evacuate or purge system with field-supplied
refrigerant.
Step 4 — Make Electrical Connections — Field
wiring must comply with local and national fire,
safety and electrical codes. Voltage to unit must be
within ± 10% of voltage indicated on nameplate.
Contact local power company for correction of
improper line voltage.
adapter must be provided (not required if 38LS
accessory tubing is used).
When a 1-1/8 in. (28.57 mm) field-supplied suc
tion line is used on 38QB042, use accessory adapter
28VQ900001 or other field-supplied connection.
Sweat connect refrigerant suction line to 1-1/8 in.
(28.57 mm) end of adapter. Connect 3/4-in.
(19.06 mm) end of adapter to unit suction line
Compatible Fitting.
Do not apply units in system where voltage may
fluctuate above or below permissible limits.
When making electrical connections, provide
clearance at unit for refrigerant piping connections.
See Table 4 for recommended wire and fuse sizes.
Mechanical Connection to Compatible Fitting
(Mate one set of connections at a time.)
1. Loosen nut on Compatible Fitting one turn. Do
not remove.
2. Remove plug and be sure O-ring is in the groove
inside the Compatible Fitting.
3. Cut tubing to correct length.
4. Insert tube into Compatible Fitting until it
bottoms.
5. Tighten nut until it bottoms on back coupler
flange. Keep tube bottomed in Compatible
Fitting while tightening nut.
Fig. 4 — Urte Power Connections
UNIT
38QB
018
024
030
036
042 230-1
AWG — American Wire Gage
FLA — Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
RLA — Rated Load Amps
‘Permissible limits of the voltage range at which the unit will
operate satisfactorily.
V/PH
208-230/1
OPER
VOLTAGE*
Max
254
254
COMPRESSOR
LRA
Min
197
207 98
48
66
82
88
Table 4 — Electrical Data (60 Hz)
FAN
FLA
RLA
124
155
15 5
20 6
199 2 40
1.25
2.40
2 40
2 40
Min Wire
Size
(AWG)t
14
12
12
10
10
Max Wire Min Gnd
(ft)
33
32
32
39
44
tCopper wire sizes based on 60 C Use copper or copper-clad
aluminum wire only Use latest NEC for copper-clad aluminum
conductor sizing
{Required when using nonmetallic conduit.
“Maximum dual element size
NOTE: All units have 24-v control circuit which requires external
power source
BRANCH CIRCUIT
Wire Sizet
m
Max Fuse or
HACR Type
CktBkrAmps“
14
12
12
10
10
25
35
35
45
45
MCA
168
21 8
21 8
28 2
27.3
Page 6
THERMOSTAT
SUBBASE
HH93AZI73
OR HH93AZI75
(38QB/40AQ 0R40QB WITHOUT ELECTRIC HEATER)
40AQ OR 40QB FAN COIL
COOLING CONTROL KIT
TERMINAL BOARD
COOLING AND ONE-STAGE HEATING
38QB
TERMINAL
BOARD
THERMOSTAT
SUBBASE
HH93AZI73
ORHH93AZI75
COOLING AND TWO-STAGE HEATING
(38QB WITH 40AQ.40QB OR 40FS/28HQ, VQ
SUPPLEMENTAL HEAT, ONE OUTDOOR THERMOSTAT)
EQUIPPED WITH ELECTRIC HEATER;
40AQ OR 40QB
ELECTRIC HEATER
TERMINAL BOARD
38QB
TERMINAL
BOARD
THERMOSTAT
SUBBASE
HH93AZI73
OR HH93AZI75
COOLING AND TWO-STAGE HEATING
(38QB WITH 40AQ,40QB OR 40FS/28HQ.VQ
SUPPLEMENTAL HEAT. NO OUTDOOR THERMOSTATS)
EQUIPPED WITH ELECTRIC HEATER;
40AQ OR 40QB
ELECTRIC HEATER
TERMINAL BOARD
B
THERMOSTAT HH07AT 171 40DQ ELEC. HEATER
WITHHH93AZI73(AUT0 (ALL MODELS)
CHANGEOVER) OR HH93AZI75 LOW VOLTAGE TERM.
(MAN CHANGEOVER) SUBBASE SPLICE CONNECTIONS
38QB
TERMINAL
BOARD
THERMOSTAT
SUBBASE
HH93AZI73 OR
HH93AZI75
COOLING AND TWO-STAGE HEATING
EQUIPPED WITH ELECTRIC HEATER;
40AQ OR 40QB
ELECTRIC HEATER
TERMINAL BOARD
(38QB WITH 40FS/28HQ,VQ
TERMINAL
SUPPLEMENTAL HEAT, TWO OUTDOOR THERMOSTATS)
38QB
TERMINAL
BOARD
38QB
BOARD
EHR — Supplemental Heat Relay
ODT — Outdoor Thermostat
-------------
-------------
Factory Wiring
Field Wiring
SUPPLEMENTAL HEAT, NO OUTDOOR THERMOSTATS)
‘Transformer (60 va) located in cooling control kit or electric heater
tRemove factory-installed jumper (Connection B) when installing outdoor thermostats (ODT)
Fig. 5 — Control Circuit Connections
Page 7
INSTALL A BRANCH CIRCUIT DISCONNECT
PER NEC of adequate size to handle unit starting
current. Provide a separate disconnect for outdoor
unit, indoor unit and for each accessory electric
' ■ heater circuit as required. (See Indoor Unit and
Electric Heater Installation, Start-Up and Service
Instructions.) Locate disconnect(s) within sight of
and readily accessible from the unit; per section
440-14 of National Electrical Code (NEC).
ROUTE LINE POWER LEADS INTO UNIT ~
Extend leads from disconnect thru power wiring
hole provided (see Fig. 1) and into unit splice area.
Remove top cover to gain access to unit wiring.
CONNECT GROUND LEAD AND POWER
WIRING — Connect ground lead to a ground lug
in control box for safety. Then connect power
wiring. See Fig. 4. Splice line power leads to yellow
and black pigtails. Use wire nuts and tape at each
connection. Connect unit wiring to copper or
copper-clad aluminum power wiring.
SEE INDOOR UNIT AND ELECTRIC HEATER
INSTALLATION, START-UP AND SERVICE
INSTRUCTIONS for line power wiring details. All
control wiring is shown in this booklet.
CONNECT CONTROL POWER WIRING (24 V)
— Extend wiring thru hole provided (Fig. 1) and
into low-voltage section of unit control ring.
Connect leads to control wiring terminal board as
shown in Fig. 5.
^ Use indoor unit transformer as 24-v supply for
system. At least a 60-va transformer is recom
mended. Carrier approved indoor units are equipped
with a 60-va transformer. See indoor unit data.
Use Carrier accessory indoor thermostat with
subbase. Table 3.
Accessory Outdoor Thermostat provides adjust
able outdoor control of accessory electric heater.
This thermostat makes contact when a drop in out
door temperature occurs. It energizes a stage of elec
tric heat when the outdoor temperature setting is
reached, provided the room thermostat is on the
second stage of heating. One outdoor thermostat is
recommended for each stage of electric heat after the
first stage. Set the outdoor thermostat(s) pro
gressively lower for each stage. Refer to heat load of
building and unit capacity to determine the correct
outdoor thermostat settings.
The accessory supplemental heat relay is required
when 2 outdoor thermostats are used. It is auto
matically energized by the manually operated
supplemental heat switch in the indoor thermo
stat subbase. The thermostat locks out compressor
and the relay bypasses the outdoor thermostats for
electric heater operation during heat pump shut
down. When one outdoor thermostat is used, a
supplemental heat relay is not required. The
supplemental heat switch in the indoor thermostat
subbase bypasses outdoor thermostat, locks out
compressor and activates electric heater.
MOUNT OUTDOOR THERMOSTAT on control
ring, to the left of the low-voltage control connec
tion. See Fig. 1.
Attach brackets with short sheet metal screws
to avoid contact with coil. Leave capillary tube
coiled in control compartment making sure it is
clear of all electrical connections and sharp metal
edges.
MOUNT SUPPLEMENTAL HEAT RELAY in
convenient location on indoor unit. Attach with
sheet metal screw.
START-UP
The 38QB unit is equipped with a crankcase
heater. It is recommended that heater be energized a
minimum of 24 hours before starting unit. To ener
gize heater only, turn the thermostat to OFF posi
tion and close electrical disconnect to heat pump.
Heat Anticipator Settings for Room Thermo
stat (HH07AT171) — Set anticipator settings for
room thermostat according to Table 5. These
settings may be changed slightly to provide a greater
degree of comfort for a particular installation.
Table 5 — Thermostat Anticipator Settings
UNIT
38Qa
( 018
\ - , 024
030
036
042
FIRSTSTAGE
ANTICIPATOR
SETTING
Fixed
INDOOR
UNIT WITH
ELECTRIC
HEATER
40DQ and
40AQ Fan Coil
with 40AQ Htrs
or 40QB Fan Coii
with 40QB Htrs
HTR
KW
50
75
100
150
20.0
25 0
30 0
34.0
SECOND-
STAGE
ANTICIPATOR
SETTINGS
25
50
75
To Start Unit — (Make sure crankcase heater
has been energized for 24 hours.) Adjust the thermo
stat as follows:
1. Set selector switch at OFF.
2. Turn on main disconnect switch(es) to indoor
and outdoor units.
3. Set fan switch as desired (ON or AUTO.).
4. Set thermostat dial at desired temperature.
5. Set selector switch at HEAT or COOL.
Check system refrigerant charge. See Refrigerant
Charging.
SERVICE
Page 8
Refrigerant Charging — The 38QB units contain
correct operating charge for complete system when
connected to28HQ,VQ,40QB or 40AQ indoor units
with 25 ft (7.6 m) of tubing of recommended diam
eter. Charge adjustment is required on other sys
tems. Adjust system charge for refrigerant line
lengths and diameters that differ from 25 ft (7.6 m)
and 3/8 in. (9.53 mm) OD (liquid line), respectively,
using refrigerant weights below. Twenty-five ft
(7.6-m), 3/8-in. (9.53-mm) OD tubing contains
14.4 oz (.4 kg) of R-22. Add R-22 charge to system
if liquid line is over 25 ft (7.6 m); remove charge
if liquid line is shorter than 25 ft (7.6 m).
When recharging is necessary during heating or
cooling season, weigh in total charge indicated in
Table 6. (Charge must be weighed in during heating
season.) Remove any refrigerant remaining in
system before recharging. If system has lost com
plete charge, triple-evacuate system to 5000 microns
(29.7 in. [100.5 kPa] vacuum) before recharging.
Service port connections are provided on liquid and
suction line service valves for evacuation and charg
ing. (See Fig. 6 for correct service port location
on cooling and heating cycles.) Dial-a-charge
charging cylinder is an accurate device used to re
charge systems by weight. These cylinders are avail
able at refrigeration supply firms.
To check and/or adjust charging during cooling
season, use correct Cooling Cycle Charging Chart
(Fig. 8, 10, 12, 14, 16) and follow Charging Chart
Method below. The charging chart may also be used
as an alternate method of recharging system.
To check system operation during heating cycle,
use correct Heating Cycle Operation Check Chart
(Fig. 9, 11, 13, 15, 17). These charts indicate
whether a correct relationship exists between system
operating pressures and air temperatures entering
indoor and outdoor units. If pressure and tempera
ture lines do not intersect on chart, the system
refrigerant charge may not be correct or other
system abnormalities may exist. Do not use Opera
tion Check Charts to adjust refrigerant charge.
Weigh charge into system.
LIQUID LINE
DIAM (in.)
3/8
5/16
1/4
0 AV (•<*
tm
urn
OUNCES OF R-22/FT LENGTH
OF LIQUID LINE
58
36
.21
M ' '
,08
Table 6 — Service Data
UNIT38QB I
R-22 CHG (lb) i
REFRIG CONTROL | AccuRater™' (Bypass Type)
FAN
Cfin
t/4
Rpm
Diam
Fig. 6 — 38QB Refrigerant Flow Diagrams
(in.)
018
1 1
4,5
1 72
3,04
m Ì
i 1
1 Ml#
1
\ 1 ' ' '
1
1800 i
14-3/4 1 ,
107S
030 1
.7,3
036 1 042
! 7,8 1 8,5
3000
20
COOLING CYCLE CHARGING CHART
METHOD
1. Operate unit a minimum of 10 minutes before
checking charge, and after each charge
adjustment.
2. Measure suction pressure by attaching a gage to
outdoor unit suction service port. (See Fig. 6
for correct service port location on cooling cycle.)
3. Measure outdoor (coil inlet) air dry-bulb tem
perature with service thermometer.
4. Using a sling psychrometer, measure wet-bulb
temperature of air entering indoor unit.
5. Refer to correct Charging Chart. Locate on
curves where outdoor air dry-bulb and indoor
air wet-bulb temperature lines intersect.
Page 9
6. From intersect point, project vertically down
ward to chart suction pressure line. Compare
chart suction pressure to unit suction pressure
(Step 2).
7. If unit suction pressure is lower than chart pres
sure, add refrigerant to system until chart
pressure is reached. If unit suction pressure is
higher than chart pressure, remove refrigerant
until chart pressure is reached.
Unit Single-Phase Compressors
COMPRESSORS OF THE SPLIT CAPACITOR
(PSC) TYPE require an equalized system pressure
to start. When supply voltage is within 10% limit and
compressor does not start, give compressor a tem
porary capacitance boost. See Carrier Standard
Service Techniques Manual, Chapter 2, for details.
mm.
Compressor Removal — See Table 7 for com
pressor information and Fig. 7 for component
location. Shut off power to unit. Remove refrigerant
from unit using refrigerant removal methods de
scribed in Carrier Standard Service Techniques
Manual, Chapter 1, Refrigerants.
Be sure system pressure is 0 psig before proceeding.
Table 7 — Compressor Data (60 Hz)
STRAINER VAPOR REVERSING "e" COIL
MUFFLER
Fig. 7 — Component Location
HOT GAS
DISCHARGE LINE
ACCUMULATOR
COMPRESSOR
coil section. Lift fan orifice/control ring after
pinching and pressing down on 3 plastic pins
of tube supports.
5. Remove louvered casing by taking out 16 screws
securing it to the cabinet and sliding it away
from the coil.
6. Using a midget tubing cutter, cut liquid and
discharge lines on the coil and suction and
discharge lines at a convenient place near the
compressor for easy reassembly with copper
slip couplings.
UNIT i
38QB i
018
024 I
030 I MD3214GE 44
V/PH
208-230/1
036,1
042 1
‘Refer to Service Parts catalog for replacement compressor model
numbers
230/1
PRODUCTION COMPRESSOR
Model*
CRA1-0150-PFV 51 1
MD2314GE 44
MD3514GE 44
PC4616BD
Oil Recharge
Ounces i
64
""TM""
1,3
1,3
Follow safety codes. Wear safety glasses and
work gloves. Have quenching cloth available.
CAUTION: Aíuíiwíusííj ititsing h m&á ir? uiüí
^ m 'phm
Oil líífesííg Of damage may result.
1. Remove top cover as described in Installation,
Step 1.
2. Disconnect high- and low-voltage field wiring
and fan motor leads from capacitor and
contactor.
3. Remove screws holding discharge grille in place.
Lift grille from unit.
4. Disconnect compressor leads (crankcase heater,
low-pressure switch, defrost thermostat and
solenoid coil) from electrical components and
pull them thru the wire access opening into the
CAliXiOK: Excmive cmpp&t
7. After plugging connections, remove condenser
coil by pinching plastic pins of tube supports
that extend into basepan and lift vertically.
Set coil on a clean, flat surface.
8. Remove compressor holddown bolts and slide
out compressor. Remove crankcase heater.
have ftm extiugaisfeef âïtdior qtjieucbifig
cîoîît m oil vapor igastes,
9. Carefully unbraze suction and discharge line
piping stubs from compressor after noting posi
tion of stubs to assist when reinstalling.
10. Install new compressor, placing crankcase
heater around compressor. Be sure compressor
holddown bolts are in place.
11. Replace coil; braze suction and discharge lines
to compressor piping stubs (at points where cut.
Step 6); rewire compressor and leak test.
12. Replace fan orifice/control ring; connect com
pressor wires after feeding them thru control
ring; replace fan/grille assembly and rewire;
Page 10
connect high- and low-voltage power wiring;
and replace louvered casing.
13. Replace top cover by running 4 screws into
orifice loosely (2 on each side of unit) and
CHARGING AND PRESSURE CHECK CHARTS
tighten when cover is in place. Replace remain
ing screws.
14. Evacuate and recharge system.
PSIG
(kPa)
(469) (483) (496) (510) (524) (538) (552) (565) (579) (593) (609)
Fig. 8 — 38QB018 with 28HQ.VQ024,
PRESSURE AT SUCTION SERVICE VALVE
40AQ024 or 40DQ024
Cooling Cycle Charging Chart
PSIG
(kPo)
(455)(469 (483)(496)(510) (524)(538) (552)(565)(579)(593)(607)
PRESSURE AT SUCTION SERVICE VALVE
Fig. 10 — 38QB024 with 28HQ,VQ030,
40AQ030 or 40DQ030
Cooling Cycle Charging Chart
(kPa) SUCTION PRESSURE AT SERVICE PORT
Fig. 9 — 38QB018 with 28HQ,VQ024,
40AQ024 or 40DQ024
Heating Cycle Operation Check Chart
Fig. 11 — 38QB024 with 28HQ,VQ030,
40AQ030 or 40DQ030
Heating Cycle Operation Check Chart
10
Page 11
PSIG
(kPa)
(427) (441) (455)(469) (483) (496)(5I0) (524)(538)(552) (565)(579)
PRESSURE AT SUCTION SERVICE VALVE
Fig. 12 — 38QB030 with 28HQ,VQ036
or 40AQ036
Cooling Cycle Charging Chart
Fig. 14 — 38QB036 with 40AQ036,
28HQ,VQ042 or 40QB042
Cooling Cycle Charging Chart
(kPa)
SUCTION PRESSURE AT SERVICE PORT
Fig. 13 — 38QB030 with 28HQ,VQ036
or 40AQ036
Heating Cycle Operation Check Chart
Fig. 15 — 38QB036 with 40AQ036,
28HQ,VQ042 or 40QB042
Heating Cycle Operation Check Chart
11
Page 12
PSIG
(kPa)
220
(1517)
68 72 76 80 84
(469) (496) (524) (552) (579)
PRESSURE AT SUCTION SERVICE VALVE
f
Fig. 16 — 38QB042 with 40QB042
or 28HQ,VQ048
Cooling Cycle Operation Check Chart
Filter Drier — Install field-supplied filter drier
(Table 3) in system liquid line when refrigerant
system is opened for service as described under
Compressor Removal. Position drier in liquid line
at convenient location.
Pumpdown Procedure — 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.
3. Start unit and run until suction pressure reaches
5 psig (35 kPa) (see Caution).
4. Shut unit off and frontseat suction valve.
5. Vent remaining pressure to atmosphere.
Fig. 17 — 38QB042 with 40QB042
or 28HQ.VQ048
Heating Cycle Operation Check Chart
suction (low side) and discharge (high side) to allow
pressure equalization.
INTERNAL CURRENT AND TEMPERATURE
SENSITIVE OVERLOAD resets automatically
when internal compressor 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 ohmmeter or continuity tester. If necessary, refer to
Carrier Standard Service Techniques Manual,
Chapter 2, for complete instructions.
LIQUID LINE LOW-PRESSURE SWITCH
(LLPS) is connected in liquid line to work with
compressor internal thermostat in providing loss-ofcharge protection during the heating cycle. Control
is mounted on liquid line.
With a high-side leak, pressure gradually de
creases until low-pressure control stops the com
pressor. (Low-pressure control settings are shown
in Tables.)
Unit Controls and Safety Devices
HIGH-PRESSURE RELIEF VALVE is located in
compressor. Relief valve opens at a pressure differ
ential of approximately 500 psig (3448 kPa) between
12
Table 8 — Pressure Switch Settings
UNIT
018
024
030
036
042
Cut-in Cutout
22 ± 5 psig
LIQUID LINE
LOW-PRESSURE SWITCH
7 ± 3psig
Page 13
With a low-side leak there is always some pressure
in the liquid line. However, compressor motor tem
perature increases because of insufficient suction
gas cooling. This causes internal thermostat to
actuate and stop compressor. When compressor
stops, system pressure equalizes and contacts on
pressure control open. The compressor cannot re
start until leak is repaired and system recharged.
CRANKCASE HEATER is connected across line
side of contactor and operates continuously.
The purpose of the heater is to keep the crankcase
warm during the off cycle and thus prevent dilution
of the oil with refrigerant. This assures good lubri
cation and prevents loss of oil from crankcase
during start-up.
To energize crankcase heater, turn thermostat to
OFF position and close electrical disconnect to heat
pump.
If the electrical disconnect switch to the outside
unit has been off for an extended period of time, the
crankcase heater should be energized for 24 hours
before starting the compressor.
DEFROST CONTROL, consisting of defrost
control board and defrost thermostat, interrupts
normal system heating operation every 90 minutes
to defrost outdoor coil, if the coil saturated suc
tion temperature indicates freezing temperatures.
Defrost control simultaneously stops outdoor fan,
energizes reversing valve solenoid to return system
to cooling cycle (outdoor unit as condenser, indoor
unit as evaporator), and activates accessory electric
heater.
For the heat pump to defrost, 2 conditions are
necessary:
1. Defrost timer contacts must be closed.
2. Refrigerant temperature from outdoor unit must
be cold enough to cause defrost thermostat con
tacts to close. Contacts close at 31 (± 4) F
(-.5 ± 2.2 C).
Every 90 minutes of elapsed running time, the de
frost timer contacts close for 10 seconds. If the
defrost thermostat contacts are closed, the unit
defrosts. 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. Defrost
thermostat contacts open at 80 (± 6)F(26.7± 3.3 C)
liquid refrigerant temperature. When defrosting is
terminated, the outdoor fan motor is energized and
reversing valve solenoid is de-energized, returning
unit to heating cycle.
HEAT PUMP CIRCUITS shown in Fig. 6 are re
frigerant flow diagrams for heating and cooling
cycles.
AccuRater™ (Bypass Type) Servicing — See
Fig. 18 for bypass type AccuRater components. The
piston has a refrigerant metering hole thru it. The
retainer forms a stop for the piston in the refrigerant
Fig. 18 — AccuRater™ (Bypass Type)
Components
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 unit down using Pumpdown Procedure
described previously.
3. Remove liquid line flare connection from
AccuRater.
4. Pull retainer out of body, being careful not to
scratch flare sealing surface. If retainer does not
pull out easily, carefully use Vise Grip pliers to
remove retainer.
5. Slide piston out by inserting a small soft wire,
with small kinks, thru metering hole. Ensure
metering hole, sealing surface around piston
cones and fluted portion of piston are not
damaged.
6. Clean piston refrigerant metering hole.
7. Replace retainer O-ring before reassembling
bypass type AccuRater. Carrier O-ring part no.
is 99CC501052.
LIQUID LINE STRAINER (protects AccuRater)
made of wire mesh is located in the liquid line inside
38QB unit behind liquid line service valve. Liquid line
is belled and sweat connected where strainer is lo
cated . If strainer is plugged, unsweat belled liquid line
connection and replace strainer. See Fig. 7.
Compatible Fitting Repair
LEAKING MECHANICAL CONNECTION —
Frontseat outdoor section service valves after reliev
ing refrigerant pressure in system. Back locknut off
Carrier Compatible Fitting onto tube. Cut fitting
between threads and O-ring shown in Fig. 19.
Fig. 19 — Carrier Compatible Fitting
13
Page 14
Remove tubing section remaining in threaded
portion of fitting. Discard locknut.
Clean, flux, and insert new tube end into remain
ing portion of Carrier Compatible Fitting. Wrap
valve base in wet rag. Heat and apply low-
temperature solder (430 F [221 C]).
LEAK SWEAT CONNECTION — Frontseat
service valves and relieve refrigerant pressure in
tubing. Clean and flux area around leak and apply
low-temperature solder (430 F [221 C]).
Condenser Fan Motor Removal
1. Shut off power to unit. Failure to do so may
result in electric shock or injury from rotating
fan blade.
2. Remove top cover as described on page 3.
3. Disconnect fan motor leads from controls.
4. Remove 6 screws holding fan motor/discharge
grille in place and lift assembly from unit.
5. Remove Carrier nameplate by straightening tabs.
6. Remove 4 nuts holding fan motor to discharge
grille. Remove motor and leads.
7. Reverse procedure for reassembly. Before replac
ing metal fan, be sure rain shield is in place on
motor shaft. Seal with Permagum around hub to
prevent entry of water between hub and shaft.
Make sure fan is positioned correctly as shown
in Fig. 20.
Fig, 20 — Condenser Fan Position
MAINTENANCE
b. Every 3 years when environment is reasonably
clean, ambient temperature is less than 105 F and
unit operating time averages 8 to 15 hours a day.
c. Every 5 years when environment is clean,
ambient temperature is less than 105 F and unit
operating time averages less than 8 hours a day.
COMPRESSOR contains factory oil charge. If oil
requires replenishment, see Table? for oil recharge
and Carrier Standard Service Techniques Manual,
Chapter 1, Refrigerants, page 1-21, for instruc
tions. Use Carrier PP33-1, Texaco Capella B or
Suniso 3G oil.
Coil Cleaning to be done at the beginning of
each cooling season or more often if required.
1. Shut off power to unit.
2. Remove louvered casing by taking out 16 screws
securing it to the cabinet and sliding it away from
the coil.
3. Clean coil using vacuum cleaner and its crevice
tool (see Fig. 21). Work crevice tool vertically
making sure tool only touches dirt on fins. To
prevent fin removal, do not “scrub” fins with
tool or move tool horizontally.
4. If oil deposits are present, spray coil with house
hold detergent (Fantastic, Lestoil, 409, or any
similar type). Wait 10 minutes then proceed to
step 5.
5. Using garden hose, spray coil vertically down
ward with a constant stream of water at moderate
pressure (see Fig. 22). Keep nozzle at a 15 to 20
degree angle, about 3 in. (76 mm) from coil face
and 18 in. (457 mm) from tube. Spray so debris is
washed out and away from coil.
6. Reinstall louvered casing being careful not to
damage coil.
7. Restore power to unit.
f
Lubrication
FAN MOTOR BEARINGS — Oiling holes are
provided at each end of condenser fan motor. Re
move fan motor and lubricate motor with 32 drops
(16 drops per hole) of SAE-10 nondetergent oil at
intervals described below.
a. Annually, when environment is very dirty,
ambient temperature is higher than 105 F, and
average unit operating time exceeds 15 hours
a day.
c.
Fig. 21 — Crevice Cleaning Tool
14
Page 15
Fig. 22 — Positioning Hose to Spray Coil
15
n
Page 16
Os
TROUBLESHOOTING CHART — COOLING CYCLE
Page 17
TROUBLESHOOTING CHART — HEATING CYCLE
Page 18
For replacement items use Carrier Specified Parts.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab
4
1
5a 5a
Form 38QB-1 SIM New
Printed in U.S A
2-82 PC 101
Catalog No 563-807
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