TM9-4120-400-1
4
1-8. LOCATION AND DESCIPTION OF MAJOR COMPONENTS. - continued
NOT E
The air conditioner can be equipped for operation in nuclear-biological-chemical (NBC)
environment by connecting filtering equipment to the fresh air filter.
22 RELIEF VALVE. This safety valve opens when the refrigerant discharge line pressure rises above
540 psig (37.97 kg/cm2).
23 CHARGING VALVE. REFRIGERANT SUCTION LINE. Provides a connection point for charging and
checking suction line pressure.
24 CHARGING VALVE. REFRIGERANT DISCHARGE LINE. Provides a connection point for charging and
checking discharge line pressure.
25 SOLENOID VALVE. PRESSURE EQUALIZING. This valve is normally open when the compressor is NOT
running to equalize the pressure at the suction and discharge sides of the compressor. It closes when the
compressor starts.
26 CONDENSER FAN AND MOTOR. This fan and motor draws outside air over the condenser coil to remove
heat from the refrigerant passing through the tubes of the condenser coil.
27 COMPRESSOR. Consists of a reciprocating compressor driven by an electrical motor, hermetically sealed
inside a steel container with a lifetime charge of oil. An external (crankcase) heater is attached to the lower part of
the container. The purpose of the heater is to prevent possible damage to the compressor caused by Iiquid
refrigerant accumulation in the crankcase during a period of shut down. The heater is connected directly to input
power and is thermostatically controlled to prevent overheating.
28 CONDENSER COIL. Made up of interconnected parallel copper tubes retained in a series of multiple,
closely spaced aluminum fins. This coil serves as a heat exchanger to remove the heat from the compressed
refrigerant vapor so that it will condense into a liquid.
from the refrigerant.
30 RECEIVER. The receiver acts as a storage tank for the liquid refrigerant.
31 SOLENOID VALVE, LIQUID LINE. This valve is normally open when the compressor is NOT running and
is thermostatically controlled during cooling cycles when operating in the COOL mode.
32 PRESSURE REGULATING VALVE. This valve regulates the suction pressure by recirculating a part of
the compressor discharge hot gas to the suction line when the suction pressure drops below a preset value. This
action prevents frosting of the evaporator coil.
33 EXPANSION VALVE. Meters refrigerant flow to the evaporator during cooling cycles when operating in
the COOL mode.
34 EVAPORATOR COIL. Similar in construction to the multiple tube, finned condenser coil. This coil serves
as a heat exchanger for the refrigerant to absorb heat from the room or enclosure air circulated through the
evaporator section.
35 HEATING ELEMENTS. Consists of two banks of heating elements. Only one bank operates in the `LOW
HEAT" mode. Both banks operate in the "HIGH HEAT' mode. One bank shuts off when the thermostat is
satisfied in both HIGH and LOW HEAT modes.
36 MIST ELIMINATOR. The purpose of the mist eliminator is to trap droplets of condensed water from the
evaporator, so that they will not be blown into the air conditioned space.
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