Refrigeration Final Test questions well
answered
True or False. Kitchen refrigerators have pressure gauges at the back of the refrigerator. - correct
answer ✔✔ False
Explain the role of pulsation dampener in a pressure gauge.
How else can you prevent vibration from affecting the gauge? - correct answer ✔✔ - dials are
filled with oil or water to reduce the vibration on gauge needles
- gauges are mounted on a separate dashboard to mitigate the effects of vibration
- prevents the flickering of the pointers due to pressure pulsations
Explain where the accumulator is located in the refrigeration system - correct answer ✔✔
Located in the compressor suction line
What is the function of the the accumulator? - correct answer ✔✔ A simple uninsulated trap
that collects and holds the liquid so that it does not enter the compressor.
How does the accumulator accomplish this function? - correct answer ✔✔ Heat is absorbed
through the uninsulated walls vaporizing the trapped liquid and returning it to the compressor
suction line
Why is a Sterne oil separator needed? - correct answer ✔✔ - Oil will enter the condenser if it is
not separated from the vapor
- The oil will coat the heat transfer surfaces, impede heat transfer and result in high compressor
discharge and increased compressor power consumption
,Explain how a Sterne oil separator works - correct answer ✔✔ - When entering the separator,
the vapor is given an abrupt change in direction. as a result, the entrained oil droplets are
thrown out of the vapor stream, collected at the bottom of the separator, and returned to the
compressor crankcase
Where is a Sterne oil separator installed? - correct answer ✔✔ In the discharge line between
the compressor and condenser
Explain how an oil trap works - correct answer ✔✔ Gauze screen permits only vapor to leave
through the vapor outlet
Oil drops hit the gauze screen and percolate at the bottom
How to prevent refrigerant vapor from condensing in the oil trap and diluting the oil in the
compressor crankcase? - correct answer ✔✔ Oil trap is kept hotter than the vapor's condensing
temperature
How is the oil trap kept hotter than the vapor's condensing temperature? - correct answer ✔✔
Keeping oil trap close to the hot compressor and protecting it from cold air drafts
What does a suction strainer do? - correct answer ✔✔ To prevent foreign particles, line scale or
corrosion from being carried with refrigerant vapor into the compressor.
Where are suction strainers installed? - correct answer ✔✔ In compressor's suction lines
How does a suction strainer work? - correct answer ✔✔ Fine mesh basket placed in strainer
housing
True or false. Suction strainer can be removed for cleaning without disconnecting any pipe. -
correct answer ✔✔ True
, Hermetic type compressors are built with.. - correct answer ✔✔ Built-in suction strainers
What are the harmful effected caused by moisture inside the refrigerant lines? - correct answer
✔✔ 1. Ice build-up in the metering device
2. Acid formation
What does a filter-drier do? - correct answer ✔✔ The main function - remove moisture from
liquid refrigerant
Also removes particulates and scale from liquid refrigerant before it flows to the metering
device
Where is a filter-drier installed? - correct answer ✔✔ In the refrigerant line ahead of expansion
valve
Name the 2 locations where a sight glass (combined with moisture indicator) is usually installed.
- correct answer ✔✔ 1. Receiver or receiver outlet
2. Between filter-drier and expansion valve
State the 2 reasons why vapor bubbles may be found in high pressure liquid refrigerant. -
correct answer ✔✔ 1. Vapor developing in the lines (cause by insufficient refrigerant in the
system)
2. Flow of liquid line restricted
A moisture indicator indicates the presence of moisture in liquid refrigerant by... - correct
answer ✔✔ Changing color
If the moisture indicator reveals the presence of moisture in liquid refrigerant, the component
that needs to be replaced is the - correct answer ✔✔ Filter-drier
answered
True or False. Kitchen refrigerators have pressure gauges at the back of the refrigerator. - correct
answer ✔✔ False
Explain the role of pulsation dampener in a pressure gauge.
How else can you prevent vibration from affecting the gauge? - correct answer ✔✔ - dials are
filled with oil or water to reduce the vibration on gauge needles
- gauges are mounted on a separate dashboard to mitigate the effects of vibration
- prevents the flickering of the pointers due to pressure pulsations
Explain where the accumulator is located in the refrigeration system - correct answer ✔✔
Located in the compressor suction line
What is the function of the the accumulator? - correct answer ✔✔ A simple uninsulated trap
that collects and holds the liquid so that it does not enter the compressor.
How does the accumulator accomplish this function? - correct answer ✔✔ Heat is absorbed
through the uninsulated walls vaporizing the trapped liquid and returning it to the compressor
suction line
Why is a Sterne oil separator needed? - correct answer ✔✔ - Oil will enter the condenser if it is
not separated from the vapor
- The oil will coat the heat transfer surfaces, impede heat transfer and result in high compressor
discharge and increased compressor power consumption
,Explain how a Sterne oil separator works - correct answer ✔✔ - When entering the separator,
the vapor is given an abrupt change in direction. as a result, the entrained oil droplets are
thrown out of the vapor stream, collected at the bottom of the separator, and returned to the
compressor crankcase
Where is a Sterne oil separator installed? - correct answer ✔✔ In the discharge line between
the compressor and condenser
Explain how an oil trap works - correct answer ✔✔ Gauze screen permits only vapor to leave
through the vapor outlet
Oil drops hit the gauze screen and percolate at the bottom
How to prevent refrigerant vapor from condensing in the oil trap and diluting the oil in the
compressor crankcase? - correct answer ✔✔ Oil trap is kept hotter than the vapor's condensing
temperature
How is the oil trap kept hotter than the vapor's condensing temperature? - correct answer ✔✔
Keeping oil trap close to the hot compressor and protecting it from cold air drafts
What does a suction strainer do? - correct answer ✔✔ To prevent foreign particles, line scale or
corrosion from being carried with refrigerant vapor into the compressor.
Where are suction strainers installed? - correct answer ✔✔ In compressor's suction lines
How does a suction strainer work? - correct answer ✔✔ Fine mesh basket placed in strainer
housing
True or false. Suction strainer can be removed for cleaning without disconnecting any pipe. -
correct answer ✔✔ True
, Hermetic type compressors are built with.. - correct answer ✔✔ Built-in suction strainers
What are the harmful effected caused by moisture inside the refrigerant lines? - correct answer
✔✔ 1. Ice build-up in the metering device
2. Acid formation
What does a filter-drier do? - correct answer ✔✔ The main function - remove moisture from
liquid refrigerant
Also removes particulates and scale from liquid refrigerant before it flows to the metering
device
Where is a filter-drier installed? - correct answer ✔✔ In the refrigerant line ahead of expansion
valve
Name the 2 locations where a sight glass (combined with moisture indicator) is usually installed.
- correct answer ✔✔ 1. Receiver or receiver outlet
2. Between filter-drier and expansion valve
State the 2 reasons why vapor bubbles may be found in high pressure liquid refrigerant. -
correct answer ✔✔ 1. Vapor developing in the lines (cause by insufficient refrigerant in the
system)
2. Flow of liquid line restricted
A moisture indicator indicates the presence of moisture in liquid refrigerant by... - correct
answer ✔✔ Changing color
If the moisture indicator reveals the presence of moisture in liquid refrigerant, the component
that needs to be replaced is the - correct answer ✔✔ Filter-drier
