EPA 608 Certification| VERIFIED Questions,
Answers & Detailed Rationales PDF |
Comprehensive HVAC Certification Study
Guide
Question 1
A technician is servicing a low-pressure centrifugal chiller
operating with R-123. During evacuation, the system pressure
rises after reaching the target vacuum. What is the most likely
cause?
A. Excess refrigerant charge
B. Non-condensables trapped in the recovery cylinder
C. A defective compressor oil heater
D. Moisture remaining in the system
Rationale: Moisture trapped within a refrigeration system can
vaporize during evacuation, causing pressure to rise after the
vacuum has been achieved. This phenomenon is known as
vacuum decay and is a common indicator that additional
dehydration is necessary. Moisture contamination can lead to
acid formation, corrosion, and reduced system efficiency.
Question 2
,Under EPA regulations, refrigerant recovery equipment
manufactured after November 15, 1993, must meet
standards established by:
A. OSHA
B. ASME
C. AHRI
D. UL
Rationale: EPA regulations require recovery and recycling
equipment to be certified by an EPA-approved testing
organization. The Air-Conditioning, Heating, and
Refrigeration Institute (AHRI) developed the performance
standards referenced by EPA for refrigerant recovery
equipment.
Question 3
Which refrigerant has the highest ozone depletion potential
(ODP)?
A. R-134a
B. R-410A
C. R-11
D. R-717
Rationale: R-11 is a chlorofluorocarbon (CFC) refrigerant
containing chlorine, which significantly contributes to ozone
depletion. Its ODP is among the highest of commonly used
,refrigerants. HFCs such as R-134a and R-410A have zero ODP,
while ammonia contains no chlorine.
Question 4
When recovering refrigerant from a system with a non-
operating compressor, the preferred recovery method is:
A. Push-pull only
B. Self-contained recovery through the high side only
C. Vapor recovery only
D. Access both high and low sides of the system
Rationale: Accessing both sides allows refrigerant to be
removed more efficiently and completely. Restricting recovery
to one side can significantly increase recovery time and may
leave refrigerant trapped in isolated sections of the system.
Question 5
A technician discovers a leak in a commercial refrigeration
system containing 120 pounds of refrigerant with a 40%
annual leak rate. What is required?
A. No action if refrigerant is recovered
B. Recharge and monitor
C. Repair the leak because the leak rate exceeds EPA
thresholds
D. Replace the refrigerant
, Rationale: EPA regulations establish leak repair requirements
for appliances exceeding specific leak-rate thresholds. A 40%
leak rate in commercial refrigeration equipment exceeds
allowable limits and requires corrective action within
prescribed timeframes.
Question 6
Why should liquid refrigerant never be added directly into the
suction side of a running compressor?
A. It increases superheat
B. It lowers condenser pressure
C. It may cause compressor damage due to liquid slugging
D. It reduces oil circulation
Rationale: Compressors are designed to compress vapor, not
liquid. Introducing liquid refrigerant directly into the suction
line can cause slugging, damaging valves, pistons, connecting
rods, or scroll elements.
Question 7
What is the primary purpose of a refrigerant receiver?
A. Remove moisture
B. Filter contaminants
C. Increase subcooling
D. Store excess liquid refrigerant
Answers & Detailed Rationales PDF |
Comprehensive HVAC Certification Study
Guide
Question 1
A technician is servicing a low-pressure centrifugal chiller
operating with R-123. During evacuation, the system pressure
rises after reaching the target vacuum. What is the most likely
cause?
A. Excess refrigerant charge
B. Non-condensables trapped in the recovery cylinder
C. A defective compressor oil heater
D. Moisture remaining in the system
Rationale: Moisture trapped within a refrigeration system can
vaporize during evacuation, causing pressure to rise after the
vacuum has been achieved. This phenomenon is known as
vacuum decay and is a common indicator that additional
dehydration is necessary. Moisture contamination can lead to
acid formation, corrosion, and reduced system efficiency.
Question 2
,Under EPA regulations, refrigerant recovery equipment
manufactured after November 15, 1993, must meet
standards established by:
A. OSHA
B. ASME
C. AHRI
D. UL
Rationale: EPA regulations require recovery and recycling
equipment to be certified by an EPA-approved testing
organization. The Air-Conditioning, Heating, and
Refrigeration Institute (AHRI) developed the performance
standards referenced by EPA for refrigerant recovery
equipment.
Question 3
Which refrigerant has the highest ozone depletion potential
(ODP)?
A. R-134a
B. R-410A
C. R-11
D. R-717
Rationale: R-11 is a chlorofluorocarbon (CFC) refrigerant
containing chlorine, which significantly contributes to ozone
depletion. Its ODP is among the highest of commonly used
,refrigerants. HFCs such as R-134a and R-410A have zero ODP,
while ammonia contains no chlorine.
Question 4
When recovering refrigerant from a system with a non-
operating compressor, the preferred recovery method is:
A. Push-pull only
B. Self-contained recovery through the high side only
C. Vapor recovery only
D. Access both high and low sides of the system
Rationale: Accessing both sides allows refrigerant to be
removed more efficiently and completely. Restricting recovery
to one side can significantly increase recovery time and may
leave refrigerant trapped in isolated sections of the system.
Question 5
A technician discovers a leak in a commercial refrigeration
system containing 120 pounds of refrigerant with a 40%
annual leak rate. What is required?
A. No action if refrigerant is recovered
B. Recharge and monitor
C. Repair the leak because the leak rate exceeds EPA
thresholds
D. Replace the refrigerant
, Rationale: EPA regulations establish leak repair requirements
for appliances exceeding specific leak-rate thresholds. A 40%
leak rate in commercial refrigeration equipment exceeds
allowable limits and requires corrective action within
prescribed timeframes.
Question 6
Why should liquid refrigerant never be added directly into the
suction side of a running compressor?
A. It increases superheat
B. It lowers condenser pressure
C. It may cause compressor damage due to liquid slugging
D. It reduces oil circulation
Rationale: Compressors are designed to compress vapor, not
liquid. Introducing liquid refrigerant directly into the suction
line can cause slugging, damaging valves, pistons, connecting
rods, or scroll elements.
Question 7
What is the primary purpose of a refrigerant receiver?
A. Remove moisture
B. Filter contaminants
C. Increase subcooling
D. Store excess liquid refrigerant
