RACT Unit 25 Practice Test Flashcards
The two forces that control the EPR valve are the _______________
a) valves spring pressure and liquid line press
b) suction line press and evaporator press
c) liquid line press and suction line press
d) evaporator press and valves spring press
d) evaporator pressure and valves spring pressure
Refrigerant relief valves come in two different types, ___________
a) electronic and mechanical
b) spring loaded and electronic
c) mechanical and one-type
d) spring-loaded and one-time
d) spring loaded and one-time
A ___________ has a magnetic coil, can be normally open or normally closed, and is frequently used to control fluid flow (liquid or vapour)
a) crankcase pressure regulator
b) evaporator pressure regulator
c) variable frequency drive
d) solenoid valve
d) solenoid valve
Pressure switches are used to start and stop electrical current flow to refrigeration components
TRUE OR FALSE
True
A control that can be used as either a low-charge protection or to control space temperature is a _________
a) thermostat
b) low-pressure switch
c) high-pressure switch
d) low ambient control
b) low-pressure switch
During an automatic pumpdown, the refrigerant is stored in the ________
a) evaporator
b) receiver
c) condenser and receiver
d) evaporator and suction line
c) condenser and receiver
A __________ is used to keep the compressor from operating with high head pressure
a) fan-cycling control
b) low-pressure control
c) head pressure regulator
d) high-pressure control
d) high pressure control
Net oil pressure is the pressure that can be measured at the discharge or outlet of the oil pump
TRUE OR FALSE
False
Any evaporator they operates below 32F _____________
a) should have a check valve at its outlet to keep up pressure during off-cycle
b) requires some form of defrost
c) must have and EPR and a TXV
d) should have a heater in the evaporator to ensure proper oil return
b) requires some form of defrost
A __________ can be used to improve the capacity of the evaporator by sub cooling the liquid refrigerant entering it
a) filter drier
b) refrigerant distributor
c) heat exchanger
d) check valve
c) heat exchanger