CFESA Refrigeration Systems 2

Question 1

Subcooling in a refrigeration system refers to:

Accepted Answer

Cooling liquid refrigerant below its condensing temperature

Answer

Subcooling ensures the liquid refrigerant is cooled below its condensing temperature, preventing flash gas before the expansion device.

Question 2

Which type of expansion device maintains a constant evaporator pressure regardless of load?

Accepted Answer

Automatic expansion valve (AXV)

Answer

The automatic expansion valve (AXV) maintains a constant evaporator pressure by responding to pressure changes at the valve outlet.

Question 3

What condition is indicated when a compressor's suction line frosts heavily all the way back to the compressor?

Accepted Answer

Overcharge of refrigerant or a flooding TXV

Answer

Heavy frosting on the suction line extending to the compressor indicates liquid refrigerant is returning to the compressor, risking liquid slugging.

Question 4

In a commercial refrigeration system, what is the role of the oil separator?

Accepted Answer

Return compressor oil from the discharge line back to the crankcase

Answer

The oil separator captures oil discharged with the hot gas and returns it to the compressor crankcase, preventing oil accumulation in the system.

Question 5

What is the typical evaporator temperature range for a commercial ice cream freezer (hardening cabinet)?

Accepted Answer

-40°F to -20°F

Answer

Hardening cabinets require very low evaporator temperatures, typically -40°F to -20°F, to rapidly freeze and maintain ice cream at proper hardness.

CFESA - Commercial Food Equipment Service Association Practice Test