Carrier 38HQ - Manual (Page 8)

CONNECT GROUND LEADS AND POWER
WIRING
Connect ground leads to the ground lug in
control box for safety. Connect power wiring. See
Fig. 8. Splice compressor section line power leads
to yellow and black pigtails, and outdoor coil power
leads to brown and blue pigtails. Use wire nuts and
tape each connection.
CONNECT POWER LEADS FROM INDOOR
COMPRESSOR SECTION TO OUTDOOR
COIL thru outdoor disconnect switch. From dis­
connect switch extend leads thru hole provided in
coil basepan (Fig. 1) and into line voltage section
of junction box, Fig. 24. Splice leads to black and
blue pigtails with wire nuts.
SEE INDOOR FAN COIL AND ELECTRIC
HEATER INSTALLATION, START-UP AND
SERVICE INSTRUCTIONS for line power wiring
details. All control wiring connections are shown
in this booklet.
CONNECT CONTROL POWER WIRING (24 v)
— Extend wiring thru 7/8-in. grommeted hole in
compressor section top panel (Fig. 2), and to control
wiring terminal board on side of control box. Con­
nect leads to terminal board as shown in Fig. 9.
Extend and connect control wiring from compressor
section to outdoor coil as required. Make splice
connections in low voltage section of coil junction
box.
Use indoor fan coil 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 4.
START-UP
The 38HQ Indoor Section Compressor is
equipped with a crankcase heater. It is recom­
mended that heater be energized a minimum of 24
hours before starting unit. To energize heater only,
turn the thermostat to OFF position and close
electrical disconnect to heat pump.
Heat Anticipator Settings for Room Thermo­
stat (HH07AT071) — Set anticipator settings for
room thermostat according to Table 6. These
settings may be changed slightly to provide a greater
degree of comfort for a particular installation.
> Table 6 — Thermostat Anticipator Settings
INDOOR
COMPR
SECTION
OUTDOOR
COIL
FIRST-
STAGE
ANTICI­
PATOR
SETTING
INDOOR
UNIT WITH
ELECTRIC
HTR
KW
SECOND-
STAGE
ANTICI­
PATOR
38HQ
HEATER SETTINGS
(Ampi
40AQ
Fan Coil 5 0
120 940 with 7 5
10.0
25
127 940
40AQ Htrs
12 0
15 0
134 940 Fixed 40FS/28HO,VQ
50
140 960
with 40FQ
Htrs
20 0
146 960
25 0
40QB Fan Coil
with 40QB Htrs.
30 0 75
Accessory Outdoor Thermostat provides adjust­
able outdoor control of accessory electric heater
(used on indoor fan coil). This thermostat makes
contact when a drop in outdoor temperature occurs.
It energizes a stage of electric 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) progressively 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-
FACTORY WIRING
Fig. 8 — Line Power Connections
8