EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is performing a major repair on a high-pressure appliance containing 10 pounds of R-407C. After recovering the refrigerant, what is the required evacuation level before recharging the system?
- A29.9 inches Hg vacuum
- B10 inches Hg vacuum
- C0 psig
- D15 inches Hg vacuum
Show answer & explanationAnswer & explanation
Correct answer: B. 10 inches Hg vacuum
For high-pressure appliances with a charge of 10 pounds or less, and after a major repair, the EPA requires evacuation to 10 inches of mercury vacuum. This ensures sufficient removal of non-condensables and moisture.
Why the other options are wrong
- A. 29.9 inches Hg vacuum is close to a perfect vacuum, typically required for very deep evacuations, but not strictly mandated for this specific scenario.
- C. 0 psig is atmospheric pressure, not a vacuum level.
- D. 15 inches Hg vacuum is required for high-pressure appliances with more than 10 lbs of refrigerant, or pre-1992 appliances with less than 10 lbs.
High-Pressure Appliance Evacuation Levels
EPA regulations specify minimum evacuation levels (vacuum) for high-pressure appliances after recovery, which vary based on charge size and type of repair.
- For major repairs on appliances with >10 lbs, 15 inches Hg vacuum is required.
- For major repairs on appliances with <=10 lbs, 10 inches Hg vacuum is required.
- These levels ensure removal of air and moisture, preventing system damage.
Memory trick: After the fix, pull a vacuum, know your pounds, avoid the doom!