Problem: Outdoor fan will start briefly but the compressor does not. Circuit breaker trips in a second. What could be causing the breaker to trip so quickly?
Answer: This sounds like you have a grounded out compressor since you say the breaker box is shutting down, tripping almost immediately when the air conditioner is turned on. I would suggest turning off your power to the unit, remove the 3 wires that go into the compressor, this would require removing the compressor terminal cover box, then testing the three terminals with an ohmmeter to see if the windings are grounded out. If they are grounded out you will need a new unit or compressor. To test you would set your meter to OHMs. You would touch one end of your test lead to a good ground like a copper pipe on your air conditioner. Then touch each of the three terminals one at a time to each of the compressor terminals (Start, Run & Common). You should not get any kind of reading on your meter. If you get any resistance readings between any of the 3 terminals and ground, then the compressor is grounded out and you will need a new compressor or AC unit. Below we have two really good Youtube videos made by KungFuMaintenance and Word of Advice TV that show how to test compressor windings to see if the windings are bad and the most common reasons why the air conditioner or heat pump keeps tripping the circuit breaker. It is easier to see what I am writing about through these two great YouTube videos! Many thanks to KungFuMaintenance and Word of Advice TV for making this informative videos. If you have any questions please feel free to email us at email@example.com or comment below. We Would Love to Help You Out and Earn Your Business!