REFRIGERATION CYCLE.-Continued - TM-5-4120-384-140034

TM5-4120-38414

1-8. REFRIGERATION CYCLE.-Continued

This unit has a bypass system which allows

Bypass System.

cooling operation at low cooling loads without cycling the

In bypass the refrigerant is piped from the

compressor on and off.

discharge to the suction side of the compressor, bypassing the

EVAPORATOR COIL (10).

W h e n the TEMPERATURE SELECTOR on the control module

senses that cooling conditions have reached the set

point, it closes the SOLENOID VALVE (7) to shut off

refrigerant flow to the EVAPORATOR COIL (10).

As the compressor suction pressure starts to drop, the

PRESSURE REGULATORS (19) open to allow flow of hot gas

from the compressor.

The QUENCH VALVE (17) senses the temperature of the gas

To prevent

at the suction side of the compressor.

excessively hot gas from reaching the compressor the

QUENCH VALVE (17) opens to allow liquid refrigerant to

mix with the hot gas.

The LINEAR ACTUATING CYLINDER ASSEMBLY (15) automatically

controls the condenser discharge louver assembly.

The SERVICE VALVES (13) are provided for charging, and

general servicing of the high and low pressure sides of

the refrigerant system.

T h e LOW PRESSURE SWITCH (20), the HIGH PRESSURE SWITCH

(16) and the PRESSURE RELIEF VALVE (14) are provided to

protect the unit from damage due to pressure extremes.

The flexible METAL HOSE ASSEMBLIES (2) and (12) provide

vibration isolation between the compressor and other

components of the refrigeration system.

1-9.

HEATING

When the MODE SELECTOR is set for HIGH heat, all six heating

These

elements, located behind the evaporator coil are energized.

elements are protected from overheating by a thermal cutout switch.

Half of the elements are thermostatically controlled by the

The remaining half are on all of the time.

TEMPERATURE SELECTOR.

When set for LOW, only the thermostatically controlled elements are

energized.

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