EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is performing a major repair on a high-pressure appliance containing 8 pounds of R-404A. According to EPA regulations, the technician must evacuate the system to what level before making the repair?
- A10 inches of mercury vacuum.
- B4 inches of mercury vacuum.
- C0 psig.
- D25 inches of mercury vacuum.
Show answer & explanationAnswer & explanation
Correct answer: B. 4 inches of mercury vacuum.
For high-pressure appliances with 0 to 10 pounds of refrigerant, the EPA requires evacuation to 0 psig or 4 inches of mercury vacuum. Since the system contains 8 pounds of R-404A (a high-pressure refrigerant), 4 inches of mercury vacuum is the correct evacuation level.
Why the other options are wrong
- A. 10 inches of mercury vacuum is required for high-pressure appliances with more than 10 pounds of refrigerant.
- C. 0 psig is an acceptable alternative to 4 inches Hg vacuum, but 4 inches Hg vacuum is a more precise vacuum level.
- D. 25 inches of mercury vacuum is a much deeper vacuum than required for recovery and is typically aimed for during full system dehydration.
High-Pressure Appliance Evacuation Levels (<10 lbs)
For high-pressure appliances containing 0 to 10 pounds of refrigerant, EPA regulations require evacuation to 0 psig or 4 inches of mercury vacuum.
- This standard applies to 'major repairs' and recovery for disposal.
- Ensures adequate removal of refrigerant to minimize emissions.
- Different levels apply for larger systems or different pressure classifications.
Memory trick: Small system, small vacuum; big system, bigger vacuum.