ESCO Light Commercial Refrigeration
(Excellence)
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS Guaranteed Pass First
Attempt!! Current Update!!
1. The suction accumulator prevents flood back from which of the following?
A. An undercharge of refrigerant
B. An evaporator fan set too high
C. Flooding after hot gas termination
D. TXV bulb clamped too tight to the suction line
- Correct Answer: C. Flooding after hot gas termination
2. When the compressor service valve is back seated, which port is closed?
A. Outlet port
B. Inlet port
C. Service port
D. Pilot port
- Correct Answer: C. Service port
3. When work on a refrigerator is complete, the compressor service valves should
be in what position?
A. Back seated
B. Front seated
C. Cracked
D. Midpoint
,- Correct Answer: A. Back seated
4. What type of oil is used with HFC refrigerant?
A. Alkyl-benzene
B. Mineral
C. Flax seed
D. Polyol Ester
- Correct Answer: D. Polyol Ester
5. On an expansion valve refrigeration system, a low pressure control can
indirectly be used for
A. Overcharge protection
B. High side cut out
C. Control refrigerant flow rate
D. Controlling box temperature
- Correct Answer: D. Controlling box temperature
6. What valve is used to connect multiple evaporators of different temperatures to
a single compressor?
A. Crank case pressure regulator (CPR)
B. Evaporator pressure regulator (EPR)
C. Oil pressure regulator
D. Head pressure regulator
- Correct Answer: B. Evaporator pressure regulator (EPR)
7. What valve is used to prevent evaporator pressure from falling below a set
limit?
A. Crank case pressure regulator (CPR)
B. Evaporator pressure regulator (EPR)
C. Oil pressure regulator
D. Head pressure regulator
- Correct Answer: B. Evaporator pressure regulator (EPR)
,8. What valve is used to control excessive pressure entering the compressor
during a hot pull down?
A. Head pressure regulator
B. Evaporator pressure regulator (EPR)
C. Crank case pressure regulator (CPR)
D. Oil pressure regulator
- Correct Answer: C. Crank case pressure regulator (CPR)
9. The oil return orifice inside a suction line accumulator is designed to
A. Return oil only during the off cycle back to the compressor
B. Maintain the same pressure in the evaporator to the inlet of the compressor
C. Meter liquid refrigerant and oil at acceptable rate
D. Equalize discharge and suction pressures during off cycle
- Correct Answer: C. Meter liquid refrigerant and oil at acceptable rate
10. Why do suction line filter dryer's have two service ports?
A. To help remove acid trapped in the dryer
B. To enable checking pressure drop across the dryer
C. One port is used for charging with liquid, the other is used for charging with
vapor
D. One port is used for adding oil, the other poor is used for adding vapor to the
system
- Correct Answer: B. To enable checking pressure drop across the dryer
11. A thermostatic expansion valve (TXV) that creates an unstable suction
pressure is said to be
A. Flashing
B. Modulating
C. Hunting
D. Fractionating
- Correct Answer: C. Hunting
, 12. Head pressure control valves permit hot gas to travel directly to the
A. Condenser
B. Evaporator
C. Liquid receiver
D. TXV
- Correct Answer: C. Liquid receiver
13. Liquid slugging of the compressor can be caused by
A. Low oil
B. TXV hunting
C. High superheat setting
D. High ambient
- Correct Answer: B. TXV hunting
14. A severe evaporator freeze up may cause
A. High discharge pressure
B. High suction pressure
C. Liquid flood back
D. Damage to TXV
- Correct Answer: C. Liquid flood back
15. The oil separator is installed in the
A. Suction line
B. Discharge line
C. Liquid line
D. Hot gas bypass line
- Correct Answer: B. Discharge line
16. If an oil separator is not used,
A. Oil traps should be installed in all vapor carrying lines
B. The system should be charged with 1/2 quart more oil
C. The system should be charged with 1/2 quart less oil
D. The system should be charged with less refrigerant
(Excellence)
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS Guaranteed Pass First
Attempt!! Current Update!!
1. The suction accumulator prevents flood back from which of the following?
A. An undercharge of refrigerant
B. An evaporator fan set too high
C. Flooding after hot gas termination
D. TXV bulb clamped too tight to the suction line
- Correct Answer: C. Flooding after hot gas termination
2. When the compressor service valve is back seated, which port is closed?
A. Outlet port
B. Inlet port
C. Service port
D. Pilot port
- Correct Answer: C. Service port
3. When work on a refrigerator is complete, the compressor service valves should
be in what position?
A. Back seated
B. Front seated
C. Cracked
D. Midpoint
,- Correct Answer: A. Back seated
4. What type of oil is used with HFC refrigerant?
A. Alkyl-benzene
B. Mineral
C. Flax seed
D. Polyol Ester
- Correct Answer: D. Polyol Ester
5. On an expansion valve refrigeration system, a low pressure control can
indirectly be used for
A. Overcharge protection
B. High side cut out
C. Control refrigerant flow rate
D. Controlling box temperature
- Correct Answer: D. Controlling box temperature
6. What valve is used to connect multiple evaporators of different temperatures to
a single compressor?
A. Crank case pressure regulator (CPR)
B. Evaporator pressure regulator (EPR)
C. Oil pressure regulator
D. Head pressure regulator
- Correct Answer: B. Evaporator pressure regulator (EPR)
7. What valve is used to prevent evaporator pressure from falling below a set
limit?
A. Crank case pressure regulator (CPR)
B. Evaporator pressure regulator (EPR)
C. Oil pressure regulator
D. Head pressure regulator
- Correct Answer: B. Evaporator pressure regulator (EPR)
,8. What valve is used to control excessive pressure entering the compressor
during a hot pull down?
A. Head pressure regulator
B. Evaporator pressure regulator (EPR)
C. Crank case pressure regulator (CPR)
D. Oil pressure regulator
- Correct Answer: C. Crank case pressure regulator (CPR)
9. The oil return orifice inside a suction line accumulator is designed to
A. Return oil only during the off cycle back to the compressor
B. Maintain the same pressure in the evaporator to the inlet of the compressor
C. Meter liquid refrigerant and oil at acceptable rate
D. Equalize discharge and suction pressures during off cycle
- Correct Answer: C. Meter liquid refrigerant and oil at acceptable rate
10. Why do suction line filter dryer's have two service ports?
A. To help remove acid trapped in the dryer
B. To enable checking pressure drop across the dryer
C. One port is used for charging with liquid, the other is used for charging with
vapor
D. One port is used for adding oil, the other poor is used for adding vapor to the
system
- Correct Answer: B. To enable checking pressure drop across the dryer
11. A thermostatic expansion valve (TXV) that creates an unstable suction
pressure is said to be
A. Flashing
B. Modulating
C. Hunting
D. Fractionating
- Correct Answer: C. Hunting
, 12. Head pressure control valves permit hot gas to travel directly to the
A. Condenser
B. Evaporator
C. Liquid receiver
D. TXV
- Correct Answer: C. Liquid receiver
13. Liquid slugging of the compressor can be caused by
A. Low oil
B. TXV hunting
C. High superheat setting
D. High ambient
- Correct Answer: B. TXV hunting
14. A severe evaporator freeze up may cause
A. High discharge pressure
B. High suction pressure
C. Liquid flood back
D. Damage to TXV
- Correct Answer: C. Liquid flood back
15. The oil separator is installed in the
A. Suction line
B. Discharge line
C. Liquid line
D. Hot gas bypass line
- Correct Answer: B. Discharge line
16. If an oil separator is not used,
A. Oil traps should be installed in all vapor carrying lines
B. The system should be charged with 1/2 quart more oil
C. The system should be charged with 1/2 quart less oil
D. The system should be charged with less refrigerant
