Carrier 38VH - Manual (Page 6)

THERMOSTAT SUBBASE
HH93AZ042 OR
THERMOSTAT SUBBASE
HH93AZ042 OR
ARRANGEMENT B-ONE TRANSFORMER
(COOLING AND ONE-STAGE HEATING)
THERMOSTAT SUBBASE
HH93AZ076
ARRANGEMENT C-ONE TRANSFORMER
(COOLING AND TWO-STAGE HEATING)
IFR, FS and IFM are located in furnace on heating-cooling
applications If accessory IFR is required for cooling only
applications, locate (IFR) in fan coil
*Connect FS to low-speed indoor fan terminal when two-speed fan
is used
fFor 28VH applications only
C — Contactor (12 va) Trans — Transformer
FS — Fan Switch ^
HC — Heating Control —z-c— Field Splice
IFM — Indoor Fan Motor ------------- pjeiq wiring
IFR — Indoor Fan Relay
S — Solenoid
------------- Factory Wiring
• Fig. 5 — Control Circuit Connections
CONNECT CONTROL POWER WIRING —
Route 24-v control wires thru hole in unit basepan
and into low-voltage section of unit junction box
(Fig. 1). Splice control leads to black and blue pigtails
on all units. See Fig. 5. Use at least 18 ga. control wire.
Use furnace or fan-coil transformer as 24-v
(40-va minimum) supply for system as shown in
Fig. 5, or, use accessory transformer shown in
Table 4.
When using 28VH coil, special wiring provisions
must be followed. See 28VH Installation, Start-Up
and Service Instructions for details.
START-UP
1. Backseat (open) liquid and suction line service
valves.
2. Set thermostat selector switch at OFF.
3. Set room thermostat at desired temperature.
Be sure this temperature is below indoor ambient.
4. Close electrical disconnects energizing entire
system.
5. Set room thermostat at COOL and fan switch at
Fan or AUTO, as desired. Solid state Time
Guard® device prevents unit from starting for up
to 5 minutes after thermostat closes (See Service,
Solid State Time Guard Circuit.) Operate unit
for 15 minutes; then check system refrigerant
charge. See Service, Refrigerant Charge, dis­
cussed later.
Motors and controls are designed to operate
satisfactorily in the voltage range shown in
Table 5. If necessary to use manifold gages for
servicing, refer to Carrier Standard Service
Techniques Manual, Chapter
1, Refrigerants,
page 1-5, Fig. 8 for bypass method of returning
charge to system. Removal of liquid line charg­
ing hose without following these precautions could
result in some loss of charge.
Refrigerant Charging
CAHTIONt To
Do not overcharge sysicio. Aa overcharge
Condensing units contain correct operating charge
for complete system when connected to Carrier-
approved evaporators (excluding 28VH applica­
tions, see “Weight Method — 28VH Applications”)
of same capacity as condensing unit and have 50 ft or
less of Carrier accessory tubing or field-supplied
tubing of recommended size. For every 10 ft of liquid
line of recommended size over 50 ft, add refrig­
erant charge as follows: .4 lb for 3/8-in. line; .28 lb
for 5 / 16-in. line. On all other systems, adjust charge
for correct operation as applicable.
r