Need alittle help on a residential compressor

[HV Mech]

I had a friend call me and said his breaker on his outdoor compressor keeps tripping. He resets it, it runs for alittle while then trips again. I told him to change his breaker. He did and when he turned the system on it now trips immediatley. I went over and tested his compressor and got no resistence on anything. c-s, c-r and s-r. I replaced the compressor and when i turned power back on it tripped immediatley again. I replaced the capacitor and its still tripping. When i pull the start wire from the capacitor i can get the fan to run, but when i connect it, the breaker trips again. I also checked to make sure the compressor isn't grounded. This is a 5 yr old system and no work has been done recently. I checked the wires to make sure nothing is bare and touching metal. HELP! I'm at a lost.:rolleyes:

[Magoo]

Apart from repeating yourself on three topics.
Did you remove all the wiring from the compressor before declaring it dead. With no resistive readings in system would suggest a dead short to ground somewhere, the fact that you remove a wire and the fan runs would indicate a ground fault somewhere. A process of elimination. Use a high voltage megger meter. Multi meters can be deceptive.

[monkey spanners]

Has your friend fitted the correct breaker?

In the uk we have three different types of breaker (mcb), B type for general loads, sockets etc, C type which has a delay on tripping to suit high inrush current devices such as motors etc, and D type which are also suitable for motors but more for transformers/welders and flourescent lights etc.

If your friend has fitted a non motor rated breaker it will trip even if the comp is ok. I note the original breaker didn't trip imediatly but the new one does, just makes me wonder. Also check the current rating, last job i did a sparky mistook a 5A breaker for a 45A breaker so even professionals get things wrong sometimes!

Jon

[goshen]

Has your friend fitted the correct breaker?

In the uk we have three different types of breaker (mcb), B type for general loads, sockets etc, C type which has a delay on tripping to suit high inrush current devices such as motors etc, and D type which are also suitable for motors but more for transformers/welders and flourescent lights etc.

If your friend has fitted a non motor rated breaker it will trip even if the comp is ok. I note the original breaker didn't trip imediatly but the new one does, just makes me wonder. Also check the current rating, last job i did a sparky mistook a 5A breaker for a 45A breaker so even professionals get things wrong sometimes!

Jon
Hi but they learn from there mistakes!!!!!!!:)

[cdub]

New member gonna throw my 2 cents in.
You said when taking the start wire off the cap the fan will run. Have u looked to see if possibly the common wire to the compressor is on the same line side as the common to the cap? assuming its a dual u could be possibly be 'single phasing' not getting proper voltage or with proper voltage pulling to many amps when trying to start with improper voltage.