EPA 608 Universal Exam
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 non-condensable 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? - ANSWER Replacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system
through: - ANSWER Leaks 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? - ANSWER HC 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
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 non-condensable 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? - ANSWER Replacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system
through: - ANSWER Leaks 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? - ANSWER HC 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
