Refrigeration Exam 100% Solved
excessive moisture being collected in the purge unit of a low-pressure refrigeration
system could indicate which probable condition? - Answer- leaking condenser or chiller
tubes
moisture in a refrigeration system can cause which of the following conditions? -
Answer- freezing the expansion valve closed, hermetic burner blowout, and corrosion of
system piping.
all the above
if the combination moisture indicator and sight glass indicates an accumulation of
moisture within the system, which of the listed procedures would be the most practical
to follow? - Answer- close the king valve, pump down the system, isolate the drier,
remove the desiccant core, and replace the new drier cartridge.
what is a quick method used to test a water-cooled condenser for the presence of a
refrigerant leak without actually pinpointing the actual location? - Answer- check the
drains on the condenser heads with a halide torch.
some chlorinated fluorocarbon refrigerants may decompose into a toxic irritating gas
under what conditions? - Answer- exposed to an open flame or hot surface
what must be done to use standard leak detection methods on a low-pressure
refrigeration system charged with refrigerant? - Answer- raise the pressure in the
system above atmospheric
to test for a suspected large refrigerant leak from an R-22 refrigeration system in an
enclosed area , how should this be done? - Answer- apply a soap solution to fittings
seen to have oil residue
which of the following statements is true concerning the testing of an R-22 refrigeration
system for leaks in an enclosed compartment with a halide torch? - Answer- halide
torches are useful in locating very small R-22 leaks
what is the color of a flame produced by a halide torch when there is no halogenated
refrigerant present at the location of the exploring tube - Answer- blue
moisture is removed from recovered refrigerant using a recycling machine by what
means? - Answer- circulating the refrigerant through a dehydrator
what must be done, at a minimum, before a system can legally be opened up for repairs
while adhering to the prohibition against the venting of halogenated fluorocarbon
refrigerants to the atmosphere? - Answer- recovery of the refrigerant
, in a refrigeration system,the push-pull technique can be used for the recovery of the
refrigerant in what state? - Answer- both liquid and vapor
in reclaiming recovered refrigerant, which type of contamination will the reclamation
process be unable to separate? - Answer- mixed refrigerants
when removing the primary refrigerant from a system using water as a secondary
refrigerant, it is important to follow which procedure(s) to safeguard the equipment? -
Answer- insure the water is drained or continually circulating to avoid freeze-up.
what is the correct color-coding of refrigerant recovery cylinders regardless of the
refrigerant contained within? - Answer- yellow top and grey body
A "hydroscopic" lubricant used in a refrigeration compressors would have what
characteristic? - Answer- having a high affinity for moisture which requires it to be kept
in a sealed container
what is the most important consideration in selecting a lubricating oil for use in a
refrigeration compressor? - Answer- have a low pour point
the lubrication oil in the crankcase of a refrigeration compressor thats shutdown is
heated. for what purpose is this done? - Answer- reduce absorption of refrigerant by the
oil
when checking the oil level in a refrigeration compressor, under what conditions would
the most accurate reading be obtained? - Answer- several minutes after shutdown,
following a prolonged period of operation.
what is the color-coding for a storage container of R-134a refrigerant? - Answer- light
blue
when a relief valve opens on a refrigeration compressor discharge line, it discharges
high pressure refrigerant vapor to what location? - Answer- suction side of the
compressor
if passive recovery is used on a small appliance fitted with a capillary tube as a metering
device with a non-operating compressor, the recovery should be made through what
means? - Answer- recovery from both high and low sides
which of the fluids listed is suitable for use as a secondary refrigerant? - Answer- brine
which of the following refrigerants is chlorine free and safe regarding atmospheric ozone
depletion? - Answer- R-134a
traditionally, which of the listed refrigerants has been more suitable than the others for
use in a centrifugal refrigeration compressor? - Answer- R-11
excessive moisture being collected in the purge unit of a low-pressure refrigeration
system could indicate which probable condition? - Answer- leaking condenser or chiller
tubes
moisture in a refrigeration system can cause which of the following conditions? -
Answer- freezing the expansion valve closed, hermetic burner blowout, and corrosion of
system piping.
all the above
if the combination moisture indicator and sight glass indicates an accumulation of
moisture within the system, which of the listed procedures would be the most practical
to follow? - Answer- close the king valve, pump down the system, isolate the drier,
remove the desiccant core, and replace the new drier cartridge.
what is a quick method used to test a water-cooled condenser for the presence of a
refrigerant leak without actually pinpointing the actual location? - Answer- check the
drains on the condenser heads with a halide torch.
some chlorinated fluorocarbon refrigerants may decompose into a toxic irritating gas
under what conditions? - Answer- exposed to an open flame or hot surface
what must be done to use standard leak detection methods on a low-pressure
refrigeration system charged with refrigerant? - Answer- raise the pressure in the
system above atmospheric
to test for a suspected large refrigerant leak from an R-22 refrigeration system in an
enclosed area , how should this be done? - Answer- apply a soap solution to fittings
seen to have oil residue
which of the following statements is true concerning the testing of an R-22 refrigeration
system for leaks in an enclosed compartment with a halide torch? - Answer- halide
torches are useful in locating very small R-22 leaks
what is the color of a flame produced by a halide torch when there is no halogenated
refrigerant present at the location of the exploring tube - Answer- blue
moisture is removed from recovered refrigerant using a recycling machine by what
means? - Answer- circulating the refrigerant through a dehydrator
what must be done, at a minimum, before a system can legally be opened up for repairs
while adhering to the prohibition against the venting of halogenated fluorocarbon
refrigerants to the atmosphere? - Answer- recovery of the refrigerant
, in a refrigeration system,the push-pull technique can be used for the recovery of the
refrigerant in what state? - Answer- both liquid and vapor
in reclaiming recovered refrigerant, which type of contamination will the reclamation
process be unable to separate? - Answer- mixed refrigerants
when removing the primary refrigerant from a system using water as a secondary
refrigerant, it is important to follow which procedure(s) to safeguard the equipment? -
Answer- insure the water is drained or continually circulating to avoid freeze-up.
what is the correct color-coding of refrigerant recovery cylinders regardless of the
refrigerant contained within? - Answer- yellow top and grey body
A "hydroscopic" lubricant used in a refrigeration compressors would have what
characteristic? - Answer- having a high affinity for moisture which requires it to be kept
in a sealed container
what is the most important consideration in selecting a lubricating oil for use in a
refrigeration compressor? - Answer- have a low pour point
the lubrication oil in the crankcase of a refrigeration compressor thats shutdown is
heated. for what purpose is this done? - Answer- reduce absorption of refrigerant by the
oil
when checking the oil level in a refrigeration compressor, under what conditions would
the most accurate reading be obtained? - Answer- several minutes after shutdown,
following a prolonged period of operation.
what is the color-coding for a storage container of R-134a refrigerant? - Answer- light
blue
when a relief valve opens on a refrigeration compressor discharge line, it discharges
high pressure refrigerant vapor to what location? - Answer- suction side of the
compressor
if passive recovery is used on a small appliance fitted with a capillary tube as a metering
device with a non-operating compressor, the recovery should be made through what
means? - Answer- recovery from both high and low sides
which of the fluids listed is suitable for use as a secondary refrigerant? - Answer- brine
which of the following refrigerants is chlorine free and safe regarding atmospheric ozone
depletion? - Answer- R-134a
traditionally, which of the listed refrigerants has been more suitable than the others for
use in a centrifugal refrigeration compressor? - Answer- R-11
