Refrigeration & Air Conditioning Mechanic Red Seal · Question
A refrigeration compressor motor fails to start, and a humming sound is heard. Voltage is present at the motor terminals. Which of the following is the most likely cause?
A humming sound with voltage present at the motor terminals, but no start, often indicates that the starting winding is open, preventing the motor from developi
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Question: A refrigeration compressor motor fails to start, and a humming sound is heard. Voltage is present at the motor terminals. Which of the following is the most likely cause?
Answer options: ✅ Open starting winding
- Shorted run winding
- Low line voltage
- Shorted starting capacitor
Correct answer: Open starting winding
Explanation: A humming sound with voltage present at the motor terminals, but no start, often indicates that the starting winding is open, preventing the motor from developing the necessary torque to begin rotation. This is common in single-phase motors.
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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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