In normal operation, what should be in the suction line returning to the compressor of an R-410A system?
Refrigeration · EPA 608 Type II. The correct answer, and the reasoning behind it.
Identifying refrigerants, system components and the state of refrigerant in each.
The question
In normal operation, what should be in the suction line returning to the compressor of an R-410A system?
- Low-pressure vaporCorrect answer
- High-pressure liquid
- High-pressure vapor
- Low-pressure liquid
Why “Low-pressure vapor” is correct
The suction line carries low-pressure vapor from the evaporator back to the compressor. Liquid there can damage the compressor, which is why accumulators are fitted.
Source: EPA: Test Topics
Why the other answers are wrong
- High-pressure liquid — High-pressure liquid is in the liquid line and receiver.
- High-pressure vapor — High-pressure vapor is in the discharge line.
- Low-pressure liquid — Liquid returning to the compressor is a fault, not normal operation.
Practice more of this
More EPA 608 Type II 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.