CFESA Refrigeration Systems 3

Question 1

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

Accepted Answer

R-404A in commercial refrigeration above 50 lbs

Answer

R-410A in residential split systems

Answer

R-134a in small appliances

Answer

R-22 in window units

Question 2

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

Accepted Answer

Ratio of cooling effect to energy input

Answer

Compressor efficiency in horsepower

Answer

Condenser heat rejection rate

Answer

Refrigerant mass flow rate

Question 3

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

Accepted Answer

Electronic expansion valves and case controllers

Answer

Suction pressure regulator

Answer

A single TXV for all cases

Answer

Liquid line solenoid on the rack

Question 4

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

Accepted Answer

Limit suction pressure entering the compressor during pulldown

Answer

Prevent high discharge pressure

Answer

Regulate oil pressure in the crankcase

Answer

Control head pressure during cold ambient conditions

Question 5

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

Accepted Answer

Low refrigerant charge causing rapid pressure equalization

Answer

Oversize expansion valve

Answer

Dirty evaporator coil

Answer

High ambient temperature

Question 6

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

Accepted Answer

Ultrasonic leak detector

Answer

Bubble solution

Answer

Electronic leak detector

Answer

UV dye with a UV lamp