Refrigeration & Air Conditioning Mechanic Red Seal · Question
A refrigeration technician is called to a grocery store where a display case is not cooling adequately. The compressor is short cycling on the low-pressure switch. The liquid line sight glass is clear when bubbling, then becomes clear again briefly before the compressor cycles off. What does this indicate?
The symptoms describe a rapid pump-down effect due to a severe restriction upstream of the evaporator (e.g., in the liquid line). The compressor pulls down the
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Question: A refrigeration technician is called to a grocery store where a display case is not cooling adequately. The compressor is short cycling on the low-pressure switch. The liquid line sight glass is clear when bubbling, then becomes clear again briefly before the compressor cycles off. What does this indicate?
Answer options:
- A faulty low-pressure switch ✅ A severe restriction in the liquid line
- An undersized evaporator coil
- Moisture in the refrigerant system
Correct answer: A severe restriction in the liquid line
Explanation: The symptoms describe a rapid pump-down effect due to a severe restriction upstream of the evaporator (e.g., in the liquid line). The compressor pulls down the suction pressure quickly, causing the low-pressure switch to open, then the pressure equalizes slightly, clearing the sight glass, and the cycle repeats.
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- Which of the following refrigerants is a hydrofluorocarbon (HFC) and has a high ozone depletion potential (ODP
- Which component is responsible for compressing the refrigerant vapour to a high pressure and temperature?
- According to the Canadian Electrical Code (CEC), what is the minimum required working clearance in front of el
- What is the main operating characteristic difference between a fixed orifice (capillary tube) and a Thermostat
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