Compression - Refrigeration System
Operations Exam Questions and
Answers
Why must you avoid running a refrigeration system below 14 kPa when pumping down -
Answer-A slightly positive system pressure is required to prevent air infiltration
This safety control device used on a centrifugal compressors allows the motor to be
started unloading - Answer-Vane closed switch
What is the purpose of the chilled water flow switch - Answer-Protects the chiller from
freezing due to lack of waterflow
Where can refrigeration system log sheets be obtained from - Answer-1. Refrigeration
system manufacturers.
2. Inspection and insurance companies.
3. Developed by the refrigeration system operator.
Which of the following is not a benefit of a preventative maintenance program - Answer-
Allows for the accumulation of all spare parts for each piece of equipment in case of a
major breakdown
What is the symptom of a refrigeration system that has high suction pressure due to an
oversized expansion valve - Answer-An abnormally cold suction line
If the compressor fails to start but the motor is running, which of the following could be a
cause - Answer-The coupling is sheared or broken
Why is it recommended that a refrigeration log sheet be used - Answer-It can indicate
changes in the system operation
The safety control in a centrifugal compressor, which ensures the compressor will only
be started under a no-load condition, it's called - Answer-Vane closed switch
Which of the following steps is not a step in the start of a reciprocating or Rotary
compressor refrigerating system - Answer-Valves in lines connecting suction gauges
should be closed
If the temperature drops 2.5 - 3°C, below the set point, this Safety control device used
on a centrifugal compressor will shut down the compressor. - Answer-Chilled water low-
temperature cut out
Vane closed switch - Answer-Allows the motor to be started under no load
Operations Exam Questions and
Answers
Why must you avoid running a refrigeration system below 14 kPa when pumping down -
Answer-A slightly positive system pressure is required to prevent air infiltration
This safety control device used on a centrifugal compressors allows the motor to be
started unloading - Answer-Vane closed switch
What is the purpose of the chilled water flow switch - Answer-Protects the chiller from
freezing due to lack of waterflow
Where can refrigeration system log sheets be obtained from - Answer-1. Refrigeration
system manufacturers.
2. Inspection and insurance companies.
3. Developed by the refrigeration system operator.
Which of the following is not a benefit of a preventative maintenance program - Answer-
Allows for the accumulation of all spare parts for each piece of equipment in case of a
major breakdown
What is the symptom of a refrigeration system that has high suction pressure due to an
oversized expansion valve - Answer-An abnormally cold suction line
If the compressor fails to start but the motor is running, which of the following could be a
cause - Answer-The coupling is sheared or broken
Why is it recommended that a refrigeration log sheet be used - Answer-It can indicate
changes in the system operation
The safety control in a centrifugal compressor, which ensures the compressor will only
be started under a no-load condition, it's called - Answer-Vane closed switch
Which of the following steps is not a step in the start of a reciprocating or Rotary
compressor refrigerating system - Answer-Valves in lines connecting suction gauges
should be closed
If the temperature drops 2.5 - 3°C, below the set point, this Safety control device used
on a centrifugal compressor will shut down the compressor. - Answer-Chilled water low-
temperature cut out
Vane closed switch - Answer-Allows the motor to be started under no load
