MA Refrigeration License Exam
What device measures the specific gravity of a substance? - answer Hydrometer
If a low-pressure chiller has a low-side leak, which of the following will most likely
result? - answer High suction pressure and High discharge pressure
A pressure vessel having an inside diameter of 6" or less shall be sufficient to withstand
____times the pressure of the saturation temperature of the refrigerant or ____times the
critical pressure of the refrigerant, whichever is less - answer2.5, 2.5
Oils, classified as to source, are - answer Animal, vegetable, mineral
Low pressure systems have what kind of compressor? - answer Centrifugal
What will occur if the strong solution in an absorption chiller becomes too strong? -
answerMachine will stop cooling and the solution will crystalize
If a liquid receiver is designed to receive the refrigerant charge during a pumpdown
procedure, it shall have the capacity to - answerReceive the pumpdown charge
How are refrigerant blends classified? - answerBased on worst case fractionation
Emergency shutdown procedures, including precautions to be observed in case of a
breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a
conspicuous card located as near as possible to the - answerCompressor
_____ and its alloys are suitable for use with ammonia systems - answerAluminium
How many gallons of water do you need per pound of ammonia? - answer1
Liquid level gauges must be provided with what? - answerAutomatic shutoff valves
The rupture disc on a low-pressure chiller typically releases pressure at - answer15 Psi
R-12. R-22, and R-40 are considered Group I refrigerants. - answerFalse
1 HP = ____ Watts? - answer746 watts
The actual expansion curve of compressor follows most nearly which one of the
following - answerAdiabatic
The color code of a tank of ammonia is - answerSilver
, What is the state of the refrigerant leaving the evaporator? - answerLow temp
superheated vapor
Low temperature systems should have what? - answerLow pour point
Which of the following most closely represents the concentration of Li-Br in a absorption
system? - answer60% Li-Br / 40% Distilled water
Which refrigerant(s) is an HFC? - answer410A
If the suction pressure is low and the evaporator temperature high, the cause will be a?
- answerStarved evaporator
An accumulator can be located between the - answerEvaporator and compressor
The pressure relief device of a positive displacement compressor shall discharge in the
______________or in accordance with 9.7.8 - answerLow side
R-123 belongs to Group - answerB-1
A secondary coolant is defined as - answerAny liquid used for the transmission of heat
without a change of state in A/C refrigeration systems having flash point above 150F
To determine the pump size needed for an open cooling tower system, the following
must be known, - answerGPM and friction head
Instead of using a compressor, an absorption air-conditioning chiller uses which of the
following as its driving force? - answerHeat
The oil separator is always inserted in the system - answerDischarge line
Class T machine room - answerNo flame producing apparatus perminantly installed
When testing systems using non-positive displacement compressors, the entire system
shall be considered for test purposes as the low side. - answerTrue
A person holding a license as a refrigeration technician may connect or disconnect for
the purpose of installation, repair, or replacement, any electrical device or control to be
a part of a refrigeration or air conditioning system, from the - answerFirst Disconnect in
Joints in piping for refrigeration containing parts must withstand temperatures of ___? -
answer700F
Trichlorotrifluoromethane - answerR-113
What device measures the specific gravity of a substance? - answer Hydrometer
If a low-pressure chiller has a low-side leak, which of the following will most likely
result? - answer High suction pressure and High discharge pressure
A pressure vessel having an inside diameter of 6" or less shall be sufficient to withstand
____times the pressure of the saturation temperature of the refrigerant or ____times the
critical pressure of the refrigerant, whichever is less - answer2.5, 2.5
Oils, classified as to source, are - answer Animal, vegetable, mineral
Low pressure systems have what kind of compressor? - answer Centrifugal
What will occur if the strong solution in an absorption chiller becomes too strong? -
answerMachine will stop cooling and the solution will crystalize
If a liquid receiver is designed to receive the refrigerant charge during a pumpdown
procedure, it shall have the capacity to - answerReceive the pumpdown charge
How are refrigerant blends classified? - answerBased on worst case fractionation
Emergency shutdown procedures, including precautions to be observed in case of a
breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a
conspicuous card located as near as possible to the - answerCompressor
_____ and its alloys are suitable for use with ammonia systems - answerAluminium
How many gallons of water do you need per pound of ammonia? - answer1
Liquid level gauges must be provided with what? - answerAutomatic shutoff valves
The rupture disc on a low-pressure chiller typically releases pressure at - answer15 Psi
R-12. R-22, and R-40 are considered Group I refrigerants. - answerFalse
1 HP = ____ Watts? - answer746 watts
The actual expansion curve of compressor follows most nearly which one of the
following - answerAdiabatic
The color code of a tank of ammonia is - answerSilver
, What is the state of the refrigerant leaving the evaporator? - answerLow temp
superheated vapor
Low temperature systems should have what? - answerLow pour point
Which of the following most closely represents the concentration of Li-Br in a absorption
system? - answer60% Li-Br / 40% Distilled water
Which refrigerant(s) is an HFC? - answer410A
If the suction pressure is low and the evaporator temperature high, the cause will be a?
- answerStarved evaporator
An accumulator can be located between the - answerEvaporator and compressor
The pressure relief device of a positive displacement compressor shall discharge in the
______________or in accordance with 9.7.8 - answerLow side
R-123 belongs to Group - answerB-1
A secondary coolant is defined as - answerAny liquid used for the transmission of heat
without a change of state in A/C refrigeration systems having flash point above 150F
To determine the pump size needed for an open cooling tower system, the following
must be known, - answerGPM and friction head
Instead of using a compressor, an absorption air-conditioning chiller uses which of the
following as its driving force? - answerHeat
The oil separator is always inserted in the system - answerDischarge line
Class T machine room - answerNo flame producing apparatus perminantly installed
When testing systems using non-positive displacement compressors, the entire system
shall be considered for test purposes as the low side. - answerTrue
A person holding a license as a refrigeration technician may connect or disconnect for
the purpose of installation, repair, or replacement, any electrical device or control to be
a part of a refrigeration or air conditioning system, from the - answerFirst Disconnect in
Joints in piping for refrigeration containing parts must withstand temperatures of ___? -
answer700F
Trichlorotrifluoromethane - answerR-113
