Before using pressure and temperature to check the refrigerant in a freezer, what condition should the…
Recovery techniques · EPA 608 Type I. The correct answer, and the reasoning behind it.
Identifying refrigerants, access valves, passive recovery and solderless fittings.
The question
Before using pressure and temperature to check the refrigerant in a freezer, what condition should the technician make sure of?
- The compressor is running at full load
- The system has been charged with nitrogen
- It has been off long enough to reach room temperatureCorrect answer
- The system has been evacuated to 4 inches of Hg vacuum
Why “It has been off long enough to reach room temperature” is correct
A P/T chart gives saturation pressure at a given temperature. The comparison works only when the refrigerant has settled to a stable temperature that the technician can measure, such as room temperature after the unit has been off.
Source: EPA: Test Topics
Why the other answers are wrong
- The compressor is running at full load — A running system has very different pressures on each side, so readings won't match a chart.
- The system has been charged with nitrogen — Nitrogen would make the pressure reading meaningless for identification.
- The system has been evacuated to 4 inches of Hg vacuum — An evacuated system has no refrigerant left to check.
Practice more of this
More EPA 608 Type I practice questions, or see every EPA 608 practice test.
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.