EPA Section 608 Universal Certification ExamCoreHard
A technician is performing a leak test on a system operating with R-123. If the system is found to be leaking, what is the required initial evacuation level before recharging, assuming the system is a low-pressure appliance?
- A2500 microns absolute.
- B25 inches Hg vacuum.
- C29.92 inches Hg vacuum (atmospheric pressure).
- D25 mm Hg absolute.
Show answer & explanationAnswer & explanation
Correct answer: D. 25 mm Hg absolute.
For low-pressure appliances like those using R-123, EPA regulations require that the system must be evacuated to an initial level of 25 millimeters of mercury (mm Hg) absolute or less before recharging. This is a much shallower vacuum than for high-pressure systems, but critical for proper operation of low-pressure chillers.
Why the other options are wrong
- A. 2500 microns (2.5 mm Hg) is a much deeper vacuum than required for initial evacuation of low-pressure appliances, though desirable for full dehydration.
- B. 25 inches Hg vacuum is still a relatively shallow vacuum and not the specific regulatory requirement.
- C. This is atmospheric pressure, not a vacuum level.
Low-Pressure Appliance Evacuation
For low-pressure appliances (e.g., R-123 chillers), EPA Section 608 regulations require an initial evacuation to 25 mm Hg absolute or lower before recharging, after a leak has been repaired.
- Specific to low-pressure appliances.
- Initial evacuation level after repair.
- Prevents non-condensables from impacting performance.
Memory trick: Low pressure, twenty-five is the measure.