EPA Section 608 Universal Certification ExamCoreEasy
A technician is performing a routine service on a high-pressure refrigeration system that uses R-410A. During the service, the technician needs to recover the refrigerant. What is the maximum allowable pressure to which the system must be evacuated during recovery before opening it for non-major repairs?
- A5 psig
- B0 psig
- C10 inches of Hg vacuum
- D0 inches of Hg vacuum
Show answer & explanationAnswer & explanation
Correct answer: C. 10 inches of Hg vacuum
For high-pressure appliances using refrigerants like R-410A, the EPA requires evacuation to 10 inches of Hg vacuum when recovering refrigerant for non-major repairs. This ensures sufficient removal of refrigerant to prevent releases.
Why the other options are wrong
- A. 5 psig indicates positive pressure, which means refrigerant is still present and not adequately recovered.
- B. 0 psig is the required level for very high-pressure appliances or for major repairs on high-pressure appliances, not typical non-major repairs for R-410A.
- D. 0 inches of Hg vacuum is atmospheric pressure (0 psig), which is insufficient for refrigerant recovery.
High-Pressure Appliance Recovery
EPA regulations specify different evacuation levels for refrigerant recovery based on the appliance's pressure classification and the type of repair being performed.
- High-pressure appliances use refrigerants with a boiling point between -50°C and 10°C at atmospheric pressure.
- Examples include R-410A, R-22, R-134a.
- Non-major repair recovery requires evacuation to 10 inches of Hg vacuum.
Memory trick: High pressure, non-major, ten inches you'll go, no more.