Trouble shooting Air Conditiioner

I have a Trane XE 1000 outside unit has tripped CB twice in the past three months. The unit does run and cool. Yesterday tripped CB and now has low buzz sound....any ideas?

thank you

Jeff

[joe]

The circuit breakers can only trip if a wire is shorted out and touching the unit, or if the compressor is going bad. The low buzzing sound you are hearing now that the unit is off is the low voltage contactor. The units is being told to come on by the thermostat, so the contactor pulls in and creates this "buzzing sound".

What to look for?

1.) With the power off, trace the wires of the compressor inside the unit. Often times, the wires will burn in two inside the compressor terminal box. If the wires are half way burned, this can cause the unit to operate sometimes, and yet trip the breaker other times.

2.) The compressor pulls the most amperage during start up. It spikes up to 80 amps, but comes right back down to 10-20 amps for operation. If the compressor is locking up and not wanting to start freely, this can prolong to the start up amp drain and cause the breaker to trip. In this case, a hard start capacitor may help you (see the link to the one below) or you will simply need to decide whether you want to change the compressor or the a/c unit as a whole.

There is always a chance of another problem that someone online would not be able to see as they are not there, but these are the two most likely causes of your compressor tripping the breaker. The good news is, it doens't trip again immediately after resetting it! The fan motor, no matter how locked up, cannot trip the breaker. Good luck!

Link to a hard start for your unit:
NorthAmericaHVAC.com
Joe