EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is performing a major repair on a high-pressure appliance containing R-410A. The system has a charge of 45 pounds. What is the minimum evacuation level required for this system before recharging?
- A10 inches of Hg vacuum
- B15 inches of Hg vacuum
- C0 inches of Hg vacuum (atmospheric pressure)
- D20 inches of Hg vacuum
Show answer & explanationAnswer & explanation
Correct answer: A. 10 inches of Hg vacuum
For high-pressure appliances with a charge greater than 20 pounds, EPA regulations require evacuation to a minimum level of 10 inches of Hg vacuum (254 mm Hg) before recharging after a major repair. This ensures that non-condensables and moisture are adequately removed from the system.
Why the other options are wrong
- B. 15 inches of Hg vacuum is not the specified minimum for high-pressure appliances with this charge size.
- C. 0 inches of Hg vacuum (atmospheric pressure) is insufficient for proper evacuation and would leave contaminants in the system.
- D. 20 inches of Hg vacuum is a common target for some systems but not the minimum for this specific scenario.
High-Pressure Appliance Evacuation (Major Repair)
For high-pressure appliances with a refrigerant charge greater than 20 pounds, a major repair requires evacuation to a minimum of 10 inches of Hg vacuum (254 mm Hg) before recharging.
- Applies to high-pressure appliances.
- Charge > 20 lbs.
- Minimum 10 inches Hg vacuum (254 mm Hg).
Memory trick: Ten is the magic number for big high-pressure repairs.