HVAC Unit 29 Troubleshooting and
Typical Operating Conditions for
Commercial Refrigeration Review
Questions and Answers
What is the first thing a technician should know before beginning troubleshooting? -
ANSWER - Knowing the correct operating pressures for a typical system. Also
knowing how the equipment is supposed to function, how it sounds, whether it
should be hot or cool, and when a fan should be operating. pg 649
What is the coil-to-air temperature relationship for a refrigeration system designed
for minimum food dehydration? ABCD - ANSWER - D) 8 - 12 F pg 650
When food dehydration is not a factor, the coil-to-air temperature relationship is
_____ to _____ F. - ANSWER - 16 to 22 pg 650
How is minimum food dehydration accomplished? - ANSWER - By keeping the
relative humidity to 90% and the temperature differential of refrigerant to air at 8 -
12 F. pg 650
Why is minimum dehydration not used on every job? - ANSWER - Not all foods need
minimum dehydration. pg 650
What is the coil-to-air temperature relationship for an average coil where
dehydration is not a factor? - ANSWER - 16 - 22 pg 650
A capillary tube system responds to an overcharge of refrigerant by? ABCD -
ANSWER - D) all of the above. It will have high suction pressure, high head pressure,
and possibly a flooded compressor. pg 659 and 660
How does TXV respond to an undercharge? - ANSWER - The system will be starved
and the suction gage and the discharge gage will read low. pg 688
Typical Operating Conditions for
Commercial Refrigeration Review
Questions and Answers
What is the first thing a technician should know before beginning troubleshooting? -
ANSWER - Knowing the correct operating pressures for a typical system. Also
knowing how the equipment is supposed to function, how it sounds, whether it
should be hot or cool, and when a fan should be operating. pg 649
What is the coil-to-air temperature relationship for a refrigeration system designed
for minimum food dehydration? ABCD - ANSWER - D) 8 - 12 F pg 650
When food dehydration is not a factor, the coil-to-air temperature relationship is
_____ to _____ F. - ANSWER - 16 to 22 pg 650
How is minimum food dehydration accomplished? - ANSWER - By keeping the
relative humidity to 90% and the temperature differential of refrigerant to air at 8 -
12 F. pg 650
Why is minimum dehydration not used on every job? - ANSWER - Not all foods need
minimum dehydration. pg 650
What is the coil-to-air temperature relationship for an average coil where
dehydration is not a factor? - ANSWER - 16 - 22 pg 650
A capillary tube system responds to an overcharge of refrigerant by? ABCD -
ANSWER - D) all of the above. It will have high suction pressure, high head pressure,
and possibly a flooded compressor. pg 659 and 660
How does TXV respond to an undercharge? - ANSWER - The system will be starved
and the suction gage and the discharge gage will read low. pg 688
