Refrigeration Systems Flashcards

Which refrigerant requires technicians to hold an EPA Section 608 Type II certification to service?

Answer: R-404A in commercial refrigeration above 50 lbs

EPA Section 608 Type II certification is required for servicing high-pressure commercial and industrial refrigeration systems containing more than 50 lbs of refrigerant.

What does a refrigeration system's COP (Coefficient of Performance) measure?

Answer: Ratio of cooling effect to energy input

COP measures refrigeration system efficiency by dividing the cooling capacity by the power input, with higher values indicating greater efficiency.

In a parallel rack refrigeration system used in supermarkets, which component controls refrigerant distribution to multiple display cases?

Answer: Electronic expansion valves and case controllers

Electronic expansion valves paired with individual case controllers precisely meter refrigerant flow to each display case in a parallel rack system.

The purpose of a crankcase pressure regulator (CPR) valve in a refrigeration system is to:

Answer: Limit suction pressure entering the compressor during pulldown

A CPR valve prevents excessive suction pressure from reaching the compressor during initial pulldown, protecting the motor from overload.

What causes a compressor to short cycle in a commercial refrigeration unit?

Answer: Low refrigerant charge causing rapid pressure equalization

A low refrigerant charge can cause the low-pressure control to cycle the compressor on and off rapidly as pressures equalize quickly.

During a refrigerant leak search on commercial equipment, which method is most effective for pinpointing small leaks in tight spaces?

Answer: Ultrasonic leak detector

Ultrasonic leak detectors can pinpoint small refrigerant leaks in confined spaces by detecting the high-frequency sound of escaping gas.