EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Hard
A technician is evacuating a high-pressure appliance containing R-404A after performing a major repair. The system has a charge of 18 pounds. What is the minimum vacuum level required before recharging?
- A0 inches of Hg vacuum (atmospheric pressure)
- B25 inches of Hg vacuum
- C15 inches of Hg vacuum
- D500 microns of Hg
Show answer & explanationAnswer & explanation
Correct answer: A. 0 inches of Hg vacuum (atmospheric pressure)
For high-pressure appliances with a charge of less than 20 pounds, EPA regulations state that after a major repair, the system must be evacuated to 0 inches of Hg vacuum (atmospheric pressure, or 0 psig) before recharging. This is a less stringent requirement than for larger systems or disposal.
Why the other options are wrong
- B. 25 inches of Hg vacuum is a significantly deeper vacuum than required for this scenario.
- C. 15 inches of Hg vacuum is not the specific EPA minimum for this charge size.
- D. 500 microns of Hg is a deep vacuum, considered best practice for dehydration, but not the *minimum* regulatory requirement for this specific scenario.
High-Pressure Appliance Evacuation (<20 lbs)
For high-pressure appliances with a refrigerant charge of less than 20 pounds, a major repair requires evacuation to a minimum of 0 inches of Hg vacuum (atmospheric pressure) before recharging.
- Applies to high-pressure appliances.
- Charge < 20 lbs.
- Minimum 0 inches Hg vacuum (atmospheric).
Memory trick: For small high-pressure systems, 'zero' inches of Hg is the repair minimum.