CFESA Refrigeration Systems 2

Question 1

Subcooling in a refrigeration system refers to:

Accepted Answer

Cooling liquid refrigerant below its condensing temperature

Answer

Cooling the suction line below ambient

Answer

Operating the evaporator below freezing

Answer

Reducing compressor discharge temperature

Question 2

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

Accepted Answer

Automatic expansion valve (AXV)

Answer

Thermostatic expansion valve (TXV)

Answer

Capillary tube

Answer

Electronic expansion valve (EEV)

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

Normal operating condition

Answer

Low refrigerant charge

Answer

High ambient temperature

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

Filter moisture from the oil

Answer

Separate refrigerant from oil in the evaporator

Answer

Prevent oil from entering the condenser

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

-10°F to 0°F

Answer

0°F to 15°F

Answer

20°F to 35°F

Question 6

A technician notices oil pooling in the evaporator of a low-temperature display case. The most appropriate corrective action is:

Accepted Answer

Verify oil return lines and compressor crankcase heater operation

Answer

Add more refrigerant

Answer

Check and increase the refrigerant charge

Answer

Replace the expansion valve