REFRIGERATION CYCLE - TM-5-4120-383-140027

TM5-4120-383-14

1-8.

REFRIGERATION

CYCLE.-Continued

q The condenser fan draws outside ambient air over and

through the two section CONDENSER COIL (3A) and (3B). The high

temperature, high pressure gas from the COMPRESSOR (1) is cooled by

the flow of air and is changed into a high pressure liquid.

q The LIQUID SIGHT GLASS (5) indicates the presence of

moisture and quantity of refrigerant in the system.

q The

DEHYDRATOR, DESICCANT, REFRIGERANT (filter/drier) (6)

removes any moisture (water vapor) or dirt that may be carried by

the liquid refrigerant.

q The SOLENOID VALVE (7) is controlled by the TEMPERATURE

SELECTOR on the control panel. This valve will shut off the flow

of refrigerant to the evaporator section when the temperature in

the conditioned area reaches the set point.

q The EXPANSION VALVE (8) controls the amount and pressure of

liquid refrigerant to the EVAPORATOR COIL (9). The EXPANSION VALVE

(8) senses the temperature and pressure of the refrigerant as it

leaves the evaporator coil. By use of the sensing bulb in the BULB

WELL (10) and an "external equalizer line" the valve constantly

adjusts the flow of liquid refrigerant to the EVAPORATOR COIL (9).

q As the liquid refrigerant leaves the EXPANSION VALVE (8) it

enters the EVAPORATOR COIL (9). As the liquid enters the coil at a

reduced pressure, the reduction in pressure and the warmer air

being forced across the tubes of the coil cause the refrigerant to

boil or "flash" to a gas. The evaporator blower circulates the

warm air from the conditioned space over and through the evaporator

coil. Liquid absorbs heat when it changes from a liquid to a gas.

AS air from the conditioned spaces comes in contact with the

EVAPORATOR COIL (9), the air is cooled.

q To prevent compressor overload and damage during start-up,

SOLENOID VALVE, pressure equalizing (16) is closed at start of

cooling cycle. This valve opens when compressor is not running to

equalize pressure on both sides of compressor.

1-11