EPA Section 608 Type III Certification
Practice Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
Pdf
1. What type of refrigerants are typically used in low-pressure appliances?
A. CFC-12
B. HFC-134a
C. HCFC-22
D. CFC-11
Answer: D. CFC-11
Rationale: Low-pressure chillers commonly use refrigerants like CFC-11 or HCFC-
123 due to their low boiling points.
2. At what pressure do low-pressure systems typically operate?
A. Above atmospheric pressure
B. At atmospheric pressure
C. Below atmospheric pressure
D. Variable high pressure
,Answer: C. Below atmospheric pressure
Rationale: Low-pressure systems operate in a vacuum, meaning pressures are
below atmospheric.
3. What is the primary concern when a leak occurs in a low-pressure system?
A. Refrigerant loss
B. Air and moisture infiltration
C. Oil contamination
D. Compressor overheating
Answer: B. Air and moisture infiltration
Rationale: Because the system operates below atmospheric pressure, leaks
allow air and moisture to enter.
4. What device is used to remove non-condensables from a low-pressure
system?
A. Filter drier
B. Recovery unit
C. Purge unit
D. Expansion valve
Answer: C. Purge unit
Rationale: Purge units remove air and other non-condensable gases that
accumulate in the system.
5. Excessive purging indicates:
A. Proper operation
B. Low refrigerant charge
C. Air leakage into the system
D. High oil level
, Answer: C. Air leakage into the system
Rationale: Frequent purging suggests air is entering due to leaks.
6. What is the EPA leak repair threshold for low-pressure appliances?
A. 5%
B. 10%
C. 15%
D. 20%
Answer: D. 20%
Rationale: The EPA requires repair if annual leak rates exceed 20% for low-
pressure appliances.
7. What happens when moisture enters a low-pressure system?
A. Increases efficiency
B. Forms acids and sludge
C. Raises pressure
D. Improves cooling
Answer: B. Forms acids and sludge
Rationale: Moisture reacts with refrigerant to form corrosive acids.
8. What is the typical evacuation level for low-pressure systems before
charging?
A. 500 microns
B. 1000 microns
C. 25 mm Hg absolute
D. 10 inches Hg
Answer: C. 25 mm Hg absolute
Rationale: Low-pressure systems use a different vacuum measurement standard.
Practice Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
1. What type of refrigerants are typically used in low-pressure appliances?
A. CFC-12
B. HFC-134a
C. HCFC-22
D. CFC-11
Answer: D. CFC-11
Rationale: Low-pressure chillers commonly use refrigerants like CFC-11 or HCFC-
123 due to their low boiling points.
2. At what pressure do low-pressure systems typically operate?
A. Above atmospheric pressure
B. At atmospheric pressure
C. Below atmospheric pressure
D. Variable high pressure
,Answer: C. Below atmospheric pressure
Rationale: Low-pressure systems operate in a vacuum, meaning pressures are
below atmospheric.
3. What is the primary concern when a leak occurs in a low-pressure system?
A. Refrigerant loss
B. Air and moisture infiltration
C. Oil contamination
D. Compressor overheating
Answer: B. Air and moisture infiltration
Rationale: Because the system operates below atmospheric pressure, leaks
allow air and moisture to enter.
4. What device is used to remove non-condensables from a low-pressure
system?
A. Filter drier
B. Recovery unit
C. Purge unit
D. Expansion valve
Answer: C. Purge unit
Rationale: Purge units remove air and other non-condensable gases that
accumulate in the system.
5. Excessive purging indicates:
A. Proper operation
B. Low refrigerant charge
C. Air leakage into the system
D. High oil level
, Answer: C. Air leakage into the system
Rationale: Frequent purging suggests air is entering due to leaks.
6. What is the EPA leak repair threshold for low-pressure appliances?
A. 5%
B. 10%
C. 15%
D. 20%
Answer: D. 20%
Rationale: The EPA requires repair if annual leak rates exceed 20% for low-
pressure appliances.
7. What happens when moisture enters a low-pressure system?
A. Increases efficiency
B. Forms acids and sludge
C. Raises pressure
D. Improves cooling
Answer: B. Forms acids and sludge
Rationale: Moisture reacts with refrigerant to form corrosive acids.
8. What is the typical evacuation level for low-pressure systems before
charging?
A. 500 microns
B. 1000 microns
C. 25 mm Hg absolute
D. 10 inches Hg
Answer: C. 25 mm Hg absolute
Rationale: Low-pressure systems use a different vacuum measurement standard.
