Commercial Refrigeration Units
29 and 30 with Complete
Questions and Answers
Which of the following is an indicator of a leaking refrigerant system? - ANSWER -
Metal-to-metal contact points.
Why will the compressor on a leaking system become overheated? - ANSWER -
There is a reduced amount of coolant.
How are trigger rates established? - ANSWER - By speed of loss.
Why does the EPA not require that all leaks be fixed? - ANSWER - Charges under fifty
pounds are exempt.
Leaks in commercial refrigeration systems must be repaired if they have an annual
leak rate of: - ANSWER - 35% of the charge per year.
Leaks in industrial process cooling systems must be repaired if they have an annual
leak rate of: - ANSWER - 35% of the charge per year.
Leaks in air conditioning systems must be repaired if they have an annual leak rate
of: - ANSWER - 15% of the charge per year.
Leaks in the refrigeration systems other than air conditioning systems, commercial
refrigeration systems, or industrial process cooling systems must be repaired if they
have an annual leak rate of: - ANSWER - 15% of the charge per year.
A technician determines that an air conditioning system which holds 50lbs of
refrigerant lost one pound of refrigerant in a month. Does EPA require the leak be
repaired? - ANSWER - Yes, because leaking 1 pound in a month is a leak rate of 24%
per year.
, What is the annual leak rate of a system holds 100lbs of refrigerant and loses three
pounds of refrigerant in a month? - ANSWER - 36%
Why has the use of halide in leak detection decreased in popularity? - ANSWER - It
doesn't work with most modern refrigerants.
Why does a pressure drop not necessarily indicate a refrigerant leak? - ANSWER - It
may be indicating a temperature change.
What is the general formula for calculating the effect of temperature on a holding
charge? - ANSWER - New temperature/starting temperature x starting pressure.
How is ultrasound used in leak detection? - ANSWER - It amplifies the sound of a
leakage.
In leak detection, R22 is used in conjunction with which of the following? - ANSWER -
With electronic detection.
Why is a pressure regulator necessary when using nitrogen cylinders? - ANSWER - To
reduce the pressure in the nitrogen cylinder to a safe level.
A refrigeration system dataplate states that the low side test pressure is 150 psig.
This means that: - ANSWER - The low side should not be pressurized above 150
psig.
If the low side test pressure is not known, the maximum pressure that should be
used for leak testing an R-22 refrigeration system with hermetic compressor is: -
ANSWER - 150 psig
What is one of the disadvantages if using dyes in leak detection? - ANSWER - They
are difficult to clean from the affected area.
29 and 30 with Complete
Questions and Answers
Which of the following is an indicator of a leaking refrigerant system? - ANSWER -
Metal-to-metal contact points.
Why will the compressor on a leaking system become overheated? - ANSWER -
There is a reduced amount of coolant.
How are trigger rates established? - ANSWER - By speed of loss.
Why does the EPA not require that all leaks be fixed? - ANSWER - Charges under fifty
pounds are exempt.
Leaks in commercial refrigeration systems must be repaired if they have an annual
leak rate of: - ANSWER - 35% of the charge per year.
Leaks in industrial process cooling systems must be repaired if they have an annual
leak rate of: - ANSWER - 35% of the charge per year.
Leaks in air conditioning systems must be repaired if they have an annual leak rate
of: - ANSWER - 15% of the charge per year.
Leaks in the refrigeration systems other than air conditioning systems, commercial
refrigeration systems, or industrial process cooling systems must be repaired if they
have an annual leak rate of: - ANSWER - 15% of the charge per year.
A technician determines that an air conditioning system which holds 50lbs of
refrigerant lost one pound of refrigerant in a month. Does EPA require the leak be
repaired? - ANSWER - Yes, because leaking 1 pound in a month is a leak rate of 24%
per year.
, What is the annual leak rate of a system holds 100lbs of refrigerant and loses three
pounds of refrigerant in a month? - ANSWER - 36%
Why has the use of halide in leak detection decreased in popularity? - ANSWER - It
doesn't work with most modern refrigerants.
Why does a pressure drop not necessarily indicate a refrigerant leak? - ANSWER - It
may be indicating a temperature change.
What is the general formula for calculating the effect of temperature on a holding
charge? - ANSWER - New temperature/starting temperature x starting pressure.
How is ultrasound used in leak detection? - ANSWER - It amplifies the sound of a
leakage.
In leak detection, R22 is used in conjunction with which of the following? - ANSWER -
With electronic detection.
Why is a pressure regulator necessary when using nitrogen cylinders? - ANSWER - To
reduce the pressure in the nitrogen cylinder to a safe level.
A refrigeration system dataplate states that the low side test pressure is 150 psig.
This means that: - ANSWER - The low side should not be pressurized above 150
psig.
If the low side test pressure is not known, the maximum pressure that should be
used for leak testing an R-22 refrigeration system with hermetic compressor is: -
ANSWER - 150 psig
What is one of the disadvantages if using dyes in leak detection? - ANSWER - They
are difficult to clean from the affected area.
