SkillCat EPA 608 EXAM: Questions Actual
Exam Questions with Correct Answers & Detailed
Rationales
1. What is a sign of a compressor burnout?
A) A loud noise
B) High pressure
C) A pungent smell
D) Low pressure
Answer: C
Rationale: A pungent smell is a sign of a compressor burnout, indicating the
motor windings have overheated and the refrigerant may be contaminated
with acids .
2. What piece of equipment should be checked for leaks on a daily
basis?
A) Vacuum pump
B) Manifold gauge set
C) Recovery device
D) Compressor
Answer: C
Rationale: Recovery equipment should be checked for leaks on a daily basis
to ensure proper operation and prevent refrigerant emissions .
3. True or false: A recovery device must achieve 4 inches of vacuum
under all circumstances.
,A) True
B) False
Answer: B
Rationale: Recovery devices do not need to achieve 4 inches of vacuum
under all circumstances. The requirement depends on the type of appliance
and the recovery method used .
4. What can remove non-condensables from a system?
A) Recovery equipment only
B) Vacuum pumps only
C) Filter dryers and flushing the system
D) Manifold gauges
Answer: C
Rationale: Filter dryers and flushing the system can remove non-
condensables from a system. Filter dryers also remove moisture and
contaminants .
5. When retrofitting a system to R-134a, which oil do you use?
A) Mineral oil
B) Alkylbenzene oil
C) Polyester (POE) oil
D) PAG oil
Answer: C
Rationale: When retrofitting a system to R-134a, you must use polyester
(POE) oil. R-134a is not miscible with mineral oil and requires POE or PAG
oil .
,6. True or false: R-1234yf is not miscible in any refrigerant oils?
A) True
B) False
Answer: B
Rationale: R-1234yf is miscible in some refrigerant oils, including POE oils.
This is important for proper lubrication in systems using this refrigerant .
7. What is a technique to speed up the recovery process?
A) Heat the recovery cylinder
B) Use smaller hoses
C) Cool the recovery cylinder
D) Recover slower
Answer: C
Rationale: Cooling the recovery cylinder helps to lower its pressure, which
speeds up the recovery process by creating a greater pressure differential .
8. After refrigerant liquid has been recovered from an appliance, any
remaining vapor is:
A) Vented to the atmosphere
B) Left in the system
C) Removed by the recovery system
D) Converted to liquid
Answer: C
, Rationale: After liquid refrigerant is recovered, the remaining vapor must be
removed by the recovery system to achieve the required vacuum level .
9. During refrigerant recovery, local municipal water supply is used to
cool the:
A) Recovery cylinder
B) Compressor
C) Water-cooled recovery unit
D) Condenser
Answer: C
Rationale: Water from the municipal supply is used to cool water-cooled
recovery units, helping to condense refrigerant vapor and speed up the
recovery process .
10. Recovering refrigerant from a system in the liquid phase will cause
the loss of:
A) Refrigerant
B) Pressure
C) Oil
D) Vacuum
Answer: C
Rationale: Recovering refrigerant in the liquid phase will cause the loss of oil
from the system. This occurs because the liquid refrigerant carries oil with it .
Exam Questions with Correct Answers & Detailed
Rationales
1. What is a sign of a compressor burnout?
A) A loud noise
B) High pressure
C) A pungent smell
D) Low pressure
Answer: C
Rationale: A pungent smell is a sign of a compressor burnout, indicating the
motor windings have overheated and the refrigerant may be contaminated
with acids .
2. What piece of equipment should be checked for leaks on a daily
basis?
A) Vacuum pump
B) Manifold gauge set
C) Recovery device
D) Compressor
Answer: C
Rationale: Recovery equipment should be checked for leaks on a daily basis
to ensure proper operation and prevent refrigerant emissions .
3. True or false: A recovery device must achieve 4 inches of vacuum
under all circumstances.
,A) True
B) False
Answer: B
Rationale: Recovery devices do not need to achieve 4 inches of vacuum
under all circumstances. The requirement depends on the type of appliance
and the recovery method used .
4. What can remove non-condensables from a system?
A) Recovery equipment only
B) Vacuum pumps only
C) Filter dryers and flushing the system
D) Manifold gauges
Answer: C
Rationale: Filter dryers and flushing the system can remove non-
condensables from a system. Filter dryers also remove moisture and
contaminants .
5. When retrofitting a system to R-134a, which oil do you use?
A) Mineral oil
B) Alkylbenzene oil
C) Polyester (POE) oil
D) PAG oil
Answer: C
Rationale: When retrofitting a system to R-134a, you must use polyester
(POE) oil. R-134a is not miscible with mineral oil and requires POE or PAG
oil .
,6. True or false: R-1234yf is not miscible in any refrigerant oils?
A) True
B) False
Answer: B
Rationale: R-1234yf is miscible in some refrigerant oils, including POE oils.
This is important for proper lubrication in systems using this refrigerant .
7. What is a technique to speed up the recovery process?
A) Heat the recovery cylinder
B) Use smaller hoses
C) Cool the recovery cylinder
D) Recover slower
Answer: C
Rationale: Cooling the recovery cylinder helps to lower its pressure, which
speeds up the recovery process by creating a greater pressure differential .
8. After refrigerant liquid has been recovered from an appliance, any
remaining vapor is:
A) Vented to the atmosphere
B) Left in the system
C) Removed by the recovery system
D) Converted to liquid
Answer: C
, Rationale: After liquid refrigerant is recovered, the remaining vapor must be
removed by the recovery system to achieve the required vacuum level .
9. During refrigerant recovery, local municipal water supply is used to
cool the:
A) Recovery cylinder
B) Compressor
C) Water-cooled recovery unit
D) Condenser
Answer: C
Rationale: Water from the municipal supply is used to cool water-cooled
recovery units, helping to condense refrigerant vapor and speed up the
recovery process .
10. Recovering refrigerant from a system in the liquid phase will cause
the loss of:
A) Refrigerant
B) Pressure
C) Oil
D) Vacuum
Answer: C
Rationale: Recovering refrigerant in the liquid phase will cause the loss of oil
from the system. This occurs because the liquid refrigerant carries oil with it .
