Causes Of AC Compressor Motor Failure

Posted on: 16 March 2023

The compressor and condenser are vital in air conditioner (AC) operations. The compressor compresses it to increase its temperature and pressure and then pumps the refrigerant to the condenser. The condenser lowers the refrigerant pressure and temperature by facilitating heat exchange.

Below are some of the reasons the compressor motor might malfunction.

The AC Lacks Power

Several AC parts, including the compressor, require electricity to run. The compressor motor won't run if:

  • You have an electrical blackout in your home and lack a backup power
  • Something has tripped the breaker where the AC connects to the electrical panel
  • Something or someone has switched off the power to the AC

Thus, the first step in the diagnosis is to see if the AC has power. If it does, the problem has affected other AC parts.

The Motor Doesn't Have Power

The electricity might not reach the compressor motor even if the AC has power. For example, the compressor motor might not get power if something burns, shorts, or disconnects the electrical line that supplies it with electricity. Secondly, the AC uses electrical relays or switches to control the electricity flow to its motors. A failed relay cuts off power to the relevant motor.

Lastly, some AC motors have safety switches that cut off power in case of electrical failure. The switch should reset automatically after the dangerous situation normalizes, but this doesn't always happen. The compressor won't run if the safety switch is stuck, even after you resolve the electrical problem.

The Motor Receives Low Voltage

AC motors require a lot of energy to run, and the system delivers electricity with high voltage. The compressor motor might fail to run or struggle to run in case of low voltage. Low voltage causes include faulty electrical connections, electrical panel issues (for example, wrong cable usage), and defective capacitors. You can only detect low voltage by measuring it.

High Refrigerant Temperature and Pressure

The compressor motor works best within specified refrigerant pressure and temperature ranges. Low refrigerant temperature and pressure overwork the motor and can lead to its failure. The compressor motor has pressure switches to protect it from low- or high-pressure cases. The switch stops the motor in case the refrigerant temperature and temperature rises dangerously.

Repairing a malfunctioning AC motor requires a professional contractor. Consult a contractor once you have confirmed the problem is not simple, like a tripped breaker, that you can resolve with DIY services. For more information on air conditioning repair, contact a professional near you.