Unit 25 Quiz

Which is not a basic component of the compression refrigeration cycle?

• Compressor

• Condenser

• Evaporator

• Suction filter

The two forces that control the EPR valve are the ________.

• suction line pressure and the evaporator pressure

• evaporator pressure and the valve’s spring pressure

• liquid line pressure and the suction line pressure

• valve’s spring pressure and the liquid line pressure

The purpose of the crankcase pressure-regulating valve is to ________.

• maintain constant pressure in the crankcase

• maintain constant pressure in the evaporator

• prevent a compressor from going into a vacuum

• prevent a compressor overload condition

Refrigerant relief valves come in two different types, ________.

• spring-loaded and electronic

• mechanical and one-type

• spring-loaded and one-time

• electronic and mechanical

A ________ has a magnetic coil, can be normally open or normally closed, and is frequently used to control fluid flow (liquid or vapor).

• evaporator pressure regulator

• crankcase pressure regulator

• solenoid valve

• variable frequency drive

Pressure switches are used to start and stop electrical current flow to refrigeration components.

• True

• False

A control that can be used as either a low-charge protection or to control space temperature is a ______.

• a. low ambient control

• b. low-pressure switch

• c. thermostat

• d. high-pressure switch

A ________ is used to keep the compressor from operating with high head pressure.

• a. head pressure regulator

• b. high-pressure control

• c. low-pressure control

• d. fan-cycling control

Net oil pressure is the pressure that can be measured at the discharge or outlet of the oil pump.

• True

• False

Any evaporator that operates below 32°F ________.

• a. should have a check valve at its outlet to keep up pressure during the off-cycle

• b. must have and EPR and a TXV

• c. should have a heater in the evaporator to ensure proper oil return

• d. requires some form of defrost