Refrigeration System Repair Flashcards
7 cards from real Air Conditioning Repair practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Refrigeration System Repair flashcards as text
A technician measures suction pressure that is too high and discharge pressure that is too low. What is the most likely cause?
Answer: Faulty compressor valves
Faulty compressor valves (worn or leaking) allow high-pressure gas to bypass back to the suction side, raising suction pressure and lowering discharge pressure.
Which refrigerant is classified as an A2L (mildly flammable) and is commonly used as a replacement for R-22 in new equipment?
Answer: R-32
R-32 is classified as A2L (mildly flammable) and is increasingly used in new equipment as an environmentally preferable alternative.
When replacing a filter-drier on a refrigeration system, what is the correct procedure after installing the new drier?
Answer: Pull a deep vacuum before recharging
After replacing a filter-drier, a deep vacuum must be pulled to remove air and moisture before recharging with refrigerant.
A refrigerant sight glass shows bubbles even though the system appears to have adequate charge. What could cause this besides low charge?
Answer: Pressure drop across a restriction in the liquid line
A restriction in the liquid line causes a pressure drop that can flash refrigerant into vapor, producing bubbles in the sight glass even with sufficient charge.
What is the purpose of a suction line accumulator in a refrigeration system?
Answer: Prevent liquid refrigerant from entering the compressor
A suction line accumulator catches any liquid refrigerant before it can reach the compressor, protecting it from liquid slugging damage.
A technician finds the compressor running but no cooling occurring and the refrigerant charge appears correct. The metering device is a TXV. What should be checked first?
Answer: TXV bulb contact and charge
A TXV with a lost bulb charge or poor bulb contact will stay closed, preventing refrigerant flow and causing a no-cooling condition.
Which condition would cause a refrigeration system to short-cycle (compressor turns on and off rapidly)?
Answer: Low refrigerant charge tripping the low-pressure switch
A low refrigerant charge causes suction pressure to drop below the low-pressure switch cutout, cycling the compressor off, then on again repeatedly.