EPA 608 UNIVERSAL EXAM 2024-2025 ACTUAL EXAM
ALL 250 QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES (VERIFIED ANSWERS)
|ALREADY GRADED A+
What are two factors that, if present, are most likely to lead to an explosion with hydrocarbon
refrigerants? - ANSWER-A sufficient concentration of the refrigeration in the space and an ignition source
An appliance normally containing more than 50 pounds of R-22 refrigerant was found to have a 35%
annual leak rate. After the repair, how many successful verification tests are required? - ANSWER-Two.
Performed before the appliance is recharged
All appliances must be equipped with a service aperture or process stub which is used when adding or
removing refrigerant from the appliance. What is typically used on small appliances? - ANSWER-A
straight piece of tubing that is entered using a piercing access valve. Process Tube
What is the primary purpose of a purge unit on a low-pressure chiller? - ANSWER-Remove
noncondensable from the system
Which of the following are recommended safe work practices when recovering refrigerants? - ANSWER-
Wear safety eyewear and butyl-lined gloves when connecting/disconnecting hoses
What is the state of the refrigerant leaving the receiver in a refrigeration system? - ANSWER-High
pressure liquid
Which of the following repairs would always be considered "major" under EPA's regulations? -
ANSWERReplacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system through: -
ANSWERLeaks from areas with gaskets or fittings
How would you remove moisture from refrigerant in a system? - ANSWER-Use a filter drier
,Where does refrigerant go after it leaves the purge unit of a low-pressure centrifugal system? - ANSWER-
The evaporator
Which refrigerants can be mixed in an appliance? - ANSWER-Refrigerants cannot be mixed
What gas should be used to leak check a system designed for use with R-410A that has been opened for
a major system repair? - ANSWER-Pressurized nitrogen
What is the term for removing refrigerant in any condition from a system and storing it in an external
container without necessarily testing or processing it in any way? - ANSWER-Recovery
What is meant by the term "high efficiency purge unit"? - ANSWER-Purge units that discharge a low
percentage of refrigerant with the air they remove
Before beginning a refrigerant recovery procedure, it is ALWAYS necessary to: - ANSWER-know the type
of refrigerant in the system
Which of the following gases is used as the baseline measurement for global warming potential? -
ANSWER-Carbon Dioxide
Which hydrocarbon refrigerant is approved for retrofit into existing household refrigerators? -
ANSWERHC R-600a 2 ounces or less
Recovered refrigerant may contain which of the following impurities? - ANSWER-Acids, moisture, and oil
A hydrostatic tube test kit will - ANSWER-determine if a lube leaks
When installing any type of access fitting onto a sealed system: - ANSWER-the fitting should be leak
tested before proceeding with recovery
A chiller with a charge of 200 pounds of an ozone-depleting refrigerant has passed the initial verification
leak test. When must a follow-up verification test be conducted? - ANSWER-Within 10 days
, Why are some hydrofluoroolefin (HFO) refrigerants classified as "A2L"? - ANSWER-They are less
flammable than hydrocarbon refrigerants, but most are still mildly flammable
To determine if the system is leaking more than the allowed rate, the EPA allows the use of which one of
the following methods to determine the full charge? - ANSWER-Use of calculations based on component
and pipe sizes
When could a reciprocating compressor be damaged if energized? - ANSWER-When the discharge
service valve is closed
Which of the following are included in EPA's definition of a "small appliance"? - ANSWER-Products
manufactured, fully charged and hermetically sealed in a factory
Recovering refrigerant from a system in the vapor phase will minimize the loss of which of the following?
- ANSWER-Oil
Which of the following is an indicator of a leak in a high-pressure system with a capillary tube? -
ANSWER-Excessive superheat
A typical setting for the high-pressure cut-out control on a recovery unit used for evacuating the
refrigerant from a low-pressure chiller is: - ANSWER-10 psig
When is it essential to take measures to help release trapped CFC, HCFC, or HFC refrigerant from the
compressor oil during refrigerant recovery? - ANSWER-When using self-contained recovery devices
Excessive running of a purge system on a low-pressure chiller generally indicates what condition? -
ANSWER-Leaking system
Which of the following always falls under the EPA definition for "major maintenance, service, or repair"?
- ANSWER-Replacing a compressor
What effect will low ambient temperatures have on recovery? - ANSWER-Increase the recovery time
ALL 250 QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES (VERIFIED ANSWERS)
|ALREADY GRADED A+
What are two factors that, if present, are most likely to lead to an explosion with hydrocarbon
refrigerants? - ANSWER-A sufficient concentration of the refrigeration in the space and an ignition source
An appliance normally containing more than 50 pounds of R-22 refrigerant was found to have a 35%
annual leak rate. After the repair, how many successful verification tests are required? - ANSWER-Two.
Performed before the appliance is recharged
All appliances must be equipped with a service aperture or process stub which is used when adding or
removing refrigerant from the appliance. What is typically used on small appliances? - ANSWER-A
straight piece of tubing that is entered using a piercing access valve. Process Tube
What is the primary purpose of a purge unit on a low-pressure chiller? - ANSWER-Remove
noncondensable from the system
Which of the following are recommended safe work practices when recovering refrigerants? - ANSWER-
Wear safety eyewear and butyl-lined gloves when connecting/disconnecting hoses
What is the state of the refrigerant leaving the receiver in a refrigeration system? - ANSWER-High
pressure liquid
Which of the following repairs would always be considered "major" under EPA's regulations? -
ANSWERReplacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system through: -
ANSWERLeaks from areas with gaskets or fittings
How would you remove moisture from refrigerant in a system? - ANSWER-Use a filter drier
,Where does refrigerant go after it leaves the purge unit of a low-pressure centrifugal system? - ANSWER-
The evaporator
Which refrigerants can be mixed in an appliance? - ANSWER-Refrigerants cannot be mixed
What gas should be used to leak check a system designed for use with R-410A that has been opened for
a major system repair? - ANSWER-Pressurized nitrogen
What is the term for removing refrigerant in any condition from a system and storing it in an external
container without necessarily testing or processing it in any way? - ANSWER-Recovery
What is meant by the term "high efficiency purge unit"? - ANSWER-Purge units that discharge a low
percentage of refrigerant with the air they remove
Before beginning a refrigerant recovery procedure, it is ALWAYS necessary to: - ANSWER-know the type
of refrigerant in the system
Which of the following gases is used as the baseline measurement for global warming potential? -
ANSWER-Carbon Dioxide
Which hydrocarbon refrigerant is approved for retrofit into existing household refrigerators? -
ANSWERHC R-600a 2 ounces or less
Recovered refrigerant may contain which of the following impurities? - ANSWER-Acids, moisture, and oil
A hydrostatic tube test kit will - ANSWER-determine if a lube leaks
When installing any type of access fitting onto a sealed system: - ANSWER-the fitting should be leak
tested before proceeding with recovery
A chiller with a charge of 200 pounds of an ozone-depleting refrigerant has passed the initial verification
leak test. When must a follow-up verification test be conducted? - ANSWER-Within 10 days
, Why are some hydrofluoroolefin (HFO) refrigerants classified as "A2L"? - ANSWER-They are less
flammable than hydrocarbon refrigerants, but most are still mildly flammable
To determine if the system is leaking more than the allowed rate, the EPA allows the use of which one of
the following methods to determine the full charge? - ANSWER-Use of calculations based on component
and pipe sizes
When could a reciprocating compressor be damaged if energized? - ANSWER-When the discharge
service valve is closed
Which of the following are included in EPA's definition of a "small appliance"? - ANSWER-Products
manufactured, fully charged and hermetically sealed in a factory
Recovering refrigerant from a system in the vapor phase will minimize the loss of which of the following?
- ANSWER-Oil
Which of the following is an indicator of a leak in a high-pressure system with a capillary tube? -
ANSWER-Excessive superheat
A typical setting for the high-pressure cut-out control on a recovery unit used for evacuating the
refrigerant from a low-pressure chiller is: - ANSWER-10 psig
When is it essential to take measures to help release trapped CFC, HCFC, or HFC refrigerant from the
compressor oil during refrigerant recovery? - ANSWER-When using self-contained recovery devices
Excessive running of a purge system on a low-pressure chiller generally indicates what condition? -
ANSWER-Leaking system
Which of the following always falls under the EPA definition for "major maintenance, service, or repair"?
- ANSWER-Replacing a compressor
What effect will low ambient temperatures have on recovery? - ANSWER-Increase the recovery time
