Testing your compressor for functionality
Issues with your AC unit may step from problems with the compressor. The most common of which is improper voltages or a poor capacitator causing outright failure or tripping of your circuit breaker.
The three types of winding problems associated with the compressor include:
- Open winding: usually caused by a damaged or disconnected wire
- Shorted winding: wire insulation failure
- Grounded winding: exposed wire making contact with the casing or ground
Troubleshooting the Compressor Motor: quick steps
- First, always disconnect the power for safety
- Remove the top from the condensing unit
- Disconnect the 3-prong plug from the compressor
- Set your multimeter to read in ohms
- Use the multimeter to measure the resistance (ohms) of each winding
What You’re Looking For:
- *Readings may vary per manufacturer and model, but should be similar to the following
- Pin 1 to Pin 2 – 3 ohms
- Pin 2 to Pin 3 – 6 ohms
- Pin 1 to Pin 3 – 9 ohms
Tips:
- The lowest of the readings should be under 10 ohms
- The next highest value should be between 2-4x higher than the lowest reading
- The highest measurement should be equal to the sum of the first two readings
If any of these are ‘off’ or you still can’t figure out the issue, its time to call a professional.