Carrier 38QB - Manual (Page 6)

Table 4 — Electrical Data (60 Hz)
UNIT
38QB
V/PH
OPER
VOLTAGE*
COMPR FAN
FLA
BRANCH CIRCUIT
Min Wire
Size (AWG)t
Max \ 'Vire ; 1 Min Gnd
Wire Sizel
Max Fuse**
or HACR Type
Ckt Bkr Amps
MCA
Max Min LRA RLA
015 208-230/1 254 197 34 7 7 1 25 14 40 1 14 15 109
018 208-230/1 254 197 48 124 1 25 14 27 1 u 25 168
024 208-230/1 254 197 66 15 5 24 12 32 ;l 12 35 21 8
030 208-230/1 254 197 82 165 24 12 32 1 12 35 23 0
036 208-230/1 254 197 88 20 6 24 10 39 1 10 45 28 2
042 230/1 254 207 98 199 24 10 44 1 10 45 27 3
048 230/1 254 207 105 22 4 24 8 62 1 10 50 30 4
060 230/1 254 207 130 27 8 24 8
51 I
60 37 2
036 208-230/3 254 197 87 11 7 24 14 32 1 14 25 170
042 208-230/3 254 197 80 13 3 24 14 29 1 14 30 190
048 208-230/3 254 197 80 16 3 24 12 24 1 12 35 22 8
060 208-230/3 254 197 98 20 9 24 10
M 10
45 28 5
036 460/3 506 414 30 5 1 1 2 14 159 1 14 15 76
042 460/3 506 414 35 72 1 2 14 120 1 14 15 102
048 460/3 506 414 40 80 1 2 14 109 1 14 15 11 2
060 460/3 506 414 49 104 1 2 14
_3I
■__________ ______
20 142
AWG — American Wire Gage
FLA — Full Load Amps
FIACR — 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
tCopper wire sizes based on 60C Use copper wire only.
tRequired when using nonmetallic conduit
“Time-delay fuse
NOTE: All units have 24-v control circuit which requires external
power source
CONNECT CONTROL POWER WIRING (24 V)
— Extend wiring thru hole provided (Fig. I) 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
suhbase, Table 3.
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 (HH0IAT171) — Set anticipator for room
^ Table 5 — Thermostat Anticipator Settings
UNIT
38QB
FIRST-
STAGE
ANTICIPATOR
SETTING
INDOOR
UNIT WITH
ELECTRIC
HEATER
HTR
KW
SECOND-
STAGE
ANTICIPATOR
SETTINGS
015
018
024
030
036
042
048
060
Fixed
40DQ and
40AQ Fan Coil
with 40AQ Htrs
or 40QB,QH
Fan Coil with
40QB Htrs
50
7 5
100
25
150
20 0
25 0 50
30 0
34 0
75
thermostat according to Table 5. These settings may
be changed slightly to provide a greater degree of
comfort for a particular installation.
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 sup­
plemental heat relay is not required. The supple­
mental 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 contaet with coil. Leave capillary tube coiled
in control compartment making sure it is clear of all
electrical connections and sharp metal edges.