REFRIGERATION CYCLE.-Continued - TM-5-4120-383-140028

TM5-4120-383-14

REFRIGERATION CYCLE.-Continued

1-8.

b. Bypass System. This unit has a bypass system which allows

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 (9).

q When

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 (9).

q As

the compressor suction pressure starts to drop, the

PRESSURE REGULATOR (11) opens to allow flow of hot gas from the

compressor.

q The

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

the suction side of the compressor. To prevent excessively hot gas

from reaching the compressor the QUENCH VALVE (17) opens to allow

liquid refrigerant to mix with the hot gas.

q The

LINEAR ACTUATING CYLINDER ASSEMBLY (15) automatically

controls the condenser discharge louver assembly.

q The

SERVICE VALVES (12) are provided for charging, and

general servicing of the high and low pressure sides of the

refrigerant system.

q The

LOW PRESSURE SWITCH (18), the HIGH PRESSURE SWITCH (14)

and the PRESSURE RELIEF VALVE (13) are provided to protect the unit

from damage due to pressure extremes.

q The

flexible METAL HOSE ASSEMBLIES (2) and (19) provide

vibration isolation between the compressor and other components of

the refrigeration system.

HEATING.

1-9.

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

elements, located behind the evaporator coil are energized. These

elements are protected from overheating by a thermal cutout switch.

Half of the elements are thermostatically controlled by the

TEMPERATURE SELECTOR. The remaining half are on all of the time.

When set for LOW, only the thermostatically controlled elements are

energized.

b. The two speed fan can be set for either HIGH or LOW

operation during heating.

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