REFRIGERATION MECHANIC LICENSING EXAM NEWEST EVALUATED EXAM
PRACTICE 120 QUESTIONS 2026-2027|ORIGINAL QUESTIONS & ANSWERS
|DETAILED RATIONALES |HINTED COMPLETE EXAM PREP GRADED
A+*INSTANT DOWNLOAD PDF*
1. A refrigeration system using R-410A is operating with a suction pressure of 118
psig. What is the approximate saturated evaporator temperature?
A) 10°F
B) 40°F
C) 55°F
D) 20°F
Answer: B - 40°F 118 psig corresponds to approximately 40°F saturation for R-
410A. This is a critical pressure-temperature relationship for checking
evaporator performance.
2. What is the primary purpose of superheat in a refrigeration system?
A) To increase compressor capacity
B) To cool the condenser
C) To ensure only vapor enters the compressor
D) To reduce discharge temperature
Answer: C - To ensure only vapor enters the compressor Superheat prevents
liquid slugging which can severely damage compressor valves and bearings. 8-
12°F is typical at the evaporator outlet.
3. A hermetic compressor is drawing high amperage and tripping on overload
shortly after starting. The most likely cause is?
A) Low refrigerant charge
B) Faulty thermostat
C) Shorted compressor windings or seized compressor
D) Dirty condenser coil
Answer: C - Shorted compressor windings or seized compressor Locked rotor
or shorted windings causes LRA (Locked Rotor Amps) draw, significantly higher
than RLA, tripping the overload protector.
4. According to EPA Section 608, what is the maximum allowable leak rate for
comfort cooling appliances containing 50 lbs or more of refrigerant?
A) 35% per year
B) 10% per year
C) 20% per year
, D) 15% per year
Answer: B - 10% per year EPA defines comfort cooling leak threshold as 10%,
commercial refrigeration 20%, and industrial process 30% for charges of 50 lbs
or more.
5. What does a high superheat reading combined with low suction pressure
indicate?
A) Overcharge
B) Undercharge or restriction in low side
C) Faulty compressor valves
D) Non-condensables in system
Answer: B - Undercharge or restriction in low side Starved evaporator cannot
absorb enough heat, resulting in low suction pressure and the remaining
refrigerant superheats excessively.
6. The function of a TXV (Thermostatic Expansion Valve) is to?
A) Control condenser pressure
B) Maintain constant superheat by regulating refrigerant flow to evaporator
C) Control compressor speed
D) Prevent liquid from entering condenser
Answer: B - Maintain constant superheat by regulating refrigerant flow to
evaporator TXV modulates flow based on bulb temperature and evaporator
pressure to maintain 8-12°F superheat.
7. What type of compressor oil is required for use with HFC refrigerants like R-
134a and R-410A?
A) Mineral oil
B) Alkylbenzene oil
C) Polyolester (POE) oil
D) PAG oil only for stationary
Answer: C - Polyolester (POE) oil POE oil is hygroscopic and miscible with
HFCs. Mineral oil is not miscible with HFCs and will cause oil return failure.
8. In a refrigeration cycle, where does subcooling occur?
A) In the evaporator outlet
B) In the condenser outlet / liquid line
C) At the compressor suction
D) At the expansion valve inlet only if flooded
Answer: B - In the condenser outlet / liquid line Subcooling is cooling liquid
, below its saturation temperature, ensuring 100% liquid to the metering device,
typically 8-15°F.
9. What is the result of non-condensable gases (air) in a refrigeration system?
A) Lower head pressure
B) Higher head pressure and higher discharge temperature
C) Lower suction pressure
D) No effect on pressures
Answer: B - Higher head pressure and higher discharge temperature Air
occupies condenser volume, reducing effective condensing surface and raising
head pressure, causing inefficiency and potential trip on high pressure.
10.A crankcase heater is used to?
A) Heat the conditioned space
B) Prevent refrigerant migration to the crankcase during off cycle
C) Increase oil viscosity
D) Boil off moisture in oil
Answer: B - Prevent refrigerant migration to the crankcase during off cycle
Refrigerant migration causes oil dilution and liquid slugging on startup. Heater
keeps crankcase warmer than evaporator.
11.What is the correct procedure for checking a hermetic compressor for a
ground?
A) Check resistance between Common and Start
B) Check resistance between any terminal and the compressor casing
C) Check voltage at terminals
D) Check capacitance
Answer: B - Check resistance between any terminal and the compressor
casing Low or zero resistance between C, S, or R terminal and the steel shell
indicates a grounded motor winding.
12.What is the purpose of a receiver in a refrigeration system?
A) To filter refrigerant
B) To store excess liquid refrigerant during varying load conditions
C) To separate oil from refrigerant
D) To meter refrigerant
Answer: B - To store excess liquid refrigerant during varying load conditions
Receiver accommodates charge variations in systems with TXV and is essential
for pump-down operation.
PRACTICE 120 QUESTIONS 2026-2027|ORIGINAL QUESTIONS & ANSWERS
|DETAILED RATIONALES |HINTED COMPLETE EXAM PREP GRADED
A+*INSTANT DOWNLOAD PDF*
1. A refrigeration system using R-410A is operating with a suction pressure of 118
psig. What is the approximate saturated evaporator temperature?
A) 10°F
B) 40°F
C) 55°F
D) 20°F
Answer: B - 40°F 118 psig corresponds to approximately 40°F saturation for R-
410A. This is a critical pressure-temperature relationship for checking
evaporator performance.
2. What is the primary purpose of superheat in a refrigeration system?
A) To increase compressor capacity
B) To cool the condenser
C) To ensure only vapor enters the compressor
D) To reduce discharge temperature
Answer: C - To ensure only vapor enters the compressor Superheat prevents
liquid slugging which can severely damage compressor valves and bearings. 8-
12°F is typical at the evaporator outlet.
3. A hermetic compressor is drawing high amperage and tripping on overload
shortly after starting. The most likely cause is?
A) Low refrigerant charge
B) Faulty thermostat
C) Shorted compressor windings or seized compressor
D) Dirty condenser coil
Answer: C - Shorted compressor windings or seized compressor Locked rotor
or shorted windings causes LRA (Locked Rotor Amps) draw, significantly higher
than RLA, tripping the overload protector.
4. According to EPA Section 608, what is the maximum allowable leak rate for
comfort cooling appliances containing 50 lbs or more of refrigerant?
A) 35% per year
B) 10% per year
C) 20% per year
, D) 15% per year
Answer: B - 10% per year EPA defines comfort cooling leak threshold as 10%,
commercial refrigeration 20%, and industrial process 30% for charges of 50 lbs
or more.
5. What does a high superheat reading combined with low suction pressure
indicate?
A) Overcharge
B) Undercharge or restriction in low side
C) Faulty compressor valves
D) Non-condensables in system
Answer: B - Undercharge or restriction in low side Starved evaporator cannot
absorb enough heat, resulting in low suction pressure and the remaining
refrigerant superheats excessively.
6. The function of a TXV (Thermostatic Expansion Valve) is to?
A) Control condenser pressure
B) Maintain constant superheat by regulating refrigerant flow to evaporator
C) Control compressor speed
D) Prevent liquid from entering condenser
Answer: B - Maintain constant superheat by regulating refrigerant flow to
evaporator TXV modulates flow based on bulb temperature and evaporator
pressure to maintain 8-12°F superheat.
7. What type of compressor oil is required for use with HFC refrigerants like R-
134a and R-410A?
A) Mineral oil
B) Alkylbenzene oil
C) Polyolester (POE) oil
D) PAG oil only for stationary
Answer: C - Polyolester (POE) oil POE oil is hygroscopic and miscible with
HFCs. Mineral oil is not miscible with HFCs and will cause oil return failure.
8. In a refrigeration cycle, where does subcooling occur?
A) In the evaporator outlet
B) In the condenser outlet / liquid line
C) At the compressor suction
D) At the expansion valve inlet only if flooded
Answer: B - In the condenser outlet / liquid line Subcooling is cooling liquid
, below its saturation temperature, ensuring 100% liquid to the metering device,
typically 8-15°F.
9. What is the result of non-condensable gases (air) in a refrigeration system?
A) Lower head pressure
B) Higher head pressure and higher discharge temperature
C) Lower suction pressure
D) No effect on pressures
Answer: B - Higher head pressure and higher discharge temperature Air
occupies condenser volume, reducing effective condensing surface and raising
head pressure, causing inefficiency and potential trip on high pressure.
10.A crankcase heater is used to?
A) Heat the conditioned space
B) Prevent refrigerant migration to the crankcase during off cycle
C) Increase oil viscosity
D) Boil off moisture in oil
Answer: B - Prevent refrigerant migration to the crankcase during off cycle
Refrigerant migration causes oil dilution and liquid slugging on startup. Heater
keeps crankcase warmer than evaporator.
11.What is the correct procedure for checking a hermetic compressor for a
ground?
A) Check resistance between Common and Start
B) Check resistance between any terminal and the compressor casing
C) Check voltage at terminals
D) Check capacitance
Answer: B - Check resistance between any terminal and the compressor
casing Low or zero resistance between C, S, or R terminal and the steel shell
indicates a grounded motor winding.
12.What is the purpose of a receiver in a refrigeration system?
A) To filter refrigerant
B) To store excess liquid refrigerant during varying load conditions
C) To separate oil from refrigerant
D) To meter refrigerant
Answer: B - To store excess liquid refrigerant during varying load conditions
Receiver accommodates charge variations in systems with TXV and is essential
for pump-down operation.
