ESCO Light Commercial Refrigeration ER sg (Updated)
(Refrigeration Systems)
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. What type of oil is used with HFC refrigerant?
a. Alkylbenzene.
b. Mineral.
c. Flaxseed.
d. Polyol ester. - Correct Answer: d. Polyol ester.
2. When a 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. 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.
,4. On an expansion valve refrigeration system, a lowpressure 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.
5. What valve is used to prevent evaporator pressure from falling below a set
limit?
a. Crankcase pressure regulator (CPR).
b. Evaporator pressure regulator (EPR).
c. Oil pressure regulator.
d. Head pressure regulator. - Correct Answer: b. Evaporator pressure
regulator (EPR).
6. What valve is used to connect multiple evaporators of different
temperatures to a single compressor?
a. Crankcase 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 control excessive pressure entering the compressor
during a hot pull down?
a. Head pressure regulator.
b. Evaporator pressure regulator (EPR).
c. Crankcase pressure regulator (CPR).
, d. Oil pressure regulator. - Correct Answer: c. Crankcase pressure
regulator (CPR).
8. 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 an acceptable rate.
d. Equalize discharge and suction pressures during off cycle. - Correct
Answer: C. Meter liquid refrigerant and oil at an acceptable rate.
9. Why do suction line filter dryers 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 port is used for adding
vapor to the system. - Correct Answer: b. To enable checking
pressure drop across the dryer.
10.Head pressure control valves permit hot gas to travel directly to:
a. Condenser.
b. Evaporator.
c. Liquid receiver.
d. TEV. - Correct Answer: a. Condenser.
11.Liquid slugging of the compressor can be caused by:
a. Low oil.
b. TEV hunting.
, c. High superheat setting.
d. High ambient. - Correct Answer: b. TEV hunting.
12.A severe evaporator freeze-up may cause:
a. High discharge pressure.
b. High suction pressure.
c. Liquid floodback.
d. Damage to the TEV. - Correct Answer: c. Liquid floodback.
13.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.
14.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 ½ quart more oil.
c. The system should be charged with ½ quart less of oil.
d. The system should be charged with less refrigerant. - Correct
Answer: a. Oil traps should be installed in all vapor carrying lines.
15.If a system has a long suction line riser an oil trap should be installed:
a. Every 6 inches of vertical rise.
b. At the top of the riser.
c. Downstream of the accumulator.
d. Every 15 to 20 feet of vertical rise. - Correct Answer: d. Every 15
to 20 feet of vertical rise.
(Refrigeration Systems)
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. What type of oil is used with HFC refrigerant?
a. Alkylbenzene.
b. Mineral.
c. Flaxseed.
d. Polyol ester. - Correct Answer: d. Polyol ester.
2. When a 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. 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.
,4. On an expansion valve refrigeration system, a lowpressure 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.
5. What valve is used to prevent evaporator pressure from falling below a set
limit?
a. Crankcase pressure regulator (CPR).
b. Evaporator pressure regulator (EPR).
c. Oil pressure regulator.
d. Head pressure regulator. - Correct Answer: b. Evaporator pressure
regulator (EPR).
6. What valve is used to connect multiple evaporators of different
temperatures to a single compressor?
a. Crankcase 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 control excessive pressure entering the compressor
during a hot pull down?
a. Head pressure regulator.
b. Evaporator pressure regulator (EPR).
c. Crankcase pressure regulator (CPR).
, d. Oil pressure regulator. - Correct Answer: c. Crankcase pressure
regulator (CPR).
8. 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 an acceptable rate.
d. Equalize discharge and suction pressures during off cycle. - Correct
Answer: C. Meter liquid refrigerant and oil at an acceptable rate.
9. Why do suction line filter dryers 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 port is used for adding
vapor to the system. - Correct Answer: b. To enable checking
pressure drop across the dryer.
10.Head pressure control valves permit hot gas to travel directly to:
a. Condenser.
b. Evaporator.
c. Liquid receiver.
d. TEV. - Correct Answer: a. Condenser.
11.Liquid slugging of the compressor can be caused by:
a. Low oil.
b. TEV hunting.
, c. High superheat setting.
d. High ambient. - Correct Answer: b. TEV hunting.
12.A severe evaporator freeze-up may cause:
a. High discharge pressure.
b. High suction pressure.
c. Liquid floodback.
d. Damage to the TEV. - Correct Answer: c. Liquid floodback.
13.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.
14.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 ½ quart more oil.
c. The system should be charged with ½ quart less of oil.
d. The system should be charged with less refrigerant. - Correct
Answer: a. Oil traps should be installed in all vapor carrying lines.
15.If a system has a long suction line riser an oil trap should be installed:
a. Every 6 inches of vertical rise.
b. At the top of the riser.
c. Downstream of the accumulator.
d. Every 15 to 20 feet of vertical rise. - Correct Answer: d. Every 15
to 20 feet of vertical rise.
