Chapter 121

Question 0

The chilling coil in an automatic purger has a primary function of:
A) lowering the operating temperature of the purger
B) keeping the system cooling while being purged
C) increasing the efficiency of the system
D) keeping discharge through the coil at the lowest available suction pressure
E) separating refrigerant vapour from the noncondensable gases to be purged

Answer 0

E) separating refrigerant vapour from the noncondensable gases to be purged

Question 1

High head pressure in a refrigerating system usually indicates:
A) broken plates in the compressor discharge valves
B) air or noncondensable gases in the system
C) broken plates in the compressor suction valves
D) lack of refrigerant in the system
E) the cooling water temperature is too low

Answer 1

B) air or noncondensable gases in the system

Question 2

A sulphur candle is used to test for _____.

Answer 2

Ammonia

Question 3

What can cause a high discharge pressure in refrigeration systems?
A) an over charged system
B) noncondensable gases
C) A & B

Answer 3

C) A & B

Question 4

Two devices used to detect leaks in a freon refrigeration system, besides soap solutions, are:
A) litmus paper and sulphur candle
B) sulphur candle and halide torch detector
C) halide torch and electronic leak detector
D) electronic leak detector and litmus paper

Answer 4

C) halide torch and electronic leak detector

Question 5

What two checks can be used to determine if charging of a refrigeration system is complete?
A) recommended weight from the manufacturer and sight glass on receiver
B) sight glass on the receiver and compressor discharge pressure
C) compressor discharge pressure and evaporator pressure
D) evaporator pressure and recommended weight from the manufacturer

Answer 5

A) recommended weight from the manufacturer and sight glass on the receiver