Carrier 30HH - Manual (Page 23)

Carrier
INSTALLATION
30HH,HJ
Tabie 8 - Pressure Contro! Settings
High Pressure
Cutout
Low Pressure
Cutout
Model
Cutout
(Psig)
Cut-in
(Psig)
Cutout
(psig)
Cut-in
(psig)
30HH 260 210 46 83
30HJ 355 255 46 83
Liquid Line Solenoid Valves (30HJ models only) -
All 30HJ condenserless models are provided with
a liquid line solenoid valve in each refrigerant
circuit. These valves and the low pressure cut­
out switches provide pumpdown control of idle
refrigerant circuits when the unit is in operation.
STARTERS AND OVERLOADS
The starters have been selected and the over­
loads have been sized at the factory to give prop­
er protection to the compressor motor. Do not
increase
their size or bypass their connections.
If trouble is encountered, the cause should be
found and corrected before the overloads are
reset.
Compressor Thermal Protection
An internal thermostat is located in the motor
windings of each compressor. Should the tem­
perature of the compressor rise too high, the
thermostat will trip and stop the compressor.
It will not restart until the temperature drops.
On
the part winding compressor, the thermo­
stat is located externally on the compressor
housing.
Crankcase Heaters
All compressors are furnished with crankcase
heaters to prevent accumulation of liquid in the
compressors. They are inserted into blind holes
in
the compressor bottom cover. Electrically,
they are wired into the control circuit by con­
necting
them to the normally closed auxiliary
contacts on the compressor starters. The crank­
case
heaters are energized at all times when
the unit is not in operation.
Electrical Characteristics: 75 watt, 230 volt,
single phase, 50/60 cycle for each crankcase
heater on 230 volt units; 75 watt, 115 volt single
phase, 50/60 cycle for 460 volt and 575 volt
units.
CIRCUIT BREAKERS
Circuit breakers provide separate branch cir­
cuit protection, one for each compressor. They
are jumpered so that only one power lead to the
unit is required.
When branch circuit overload causes the break­
ers to trip, they must be manually reset, by
throwing the switch off and on again. The cause
of the overload should be determined and rem­
edied before restarting.
Control Circuit
To stop unit, push ’’STOP-START"
center of the gage panel.
button in
Table 9 - Circuit Breaker Trip Amperes
Circuit Breaker Size (Amps)
Compressor and Unit
208-3-60
230-3-60
230-3-50
460-3-60
400-3-50
575-3-60
6D73 (HH) 90 90 40 40
6D75 (HJ) 90 90 50 40
6D68 (HH) 50 50 25 20
6D68 (HJ) 70 50 30 30
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