[Paul.le]

I have a 3 years old condenser AC outside unit. Not sure what happen. It trip service breaker every time it starts. I checked start capacitor and contactor and they are good. Any thought is appreciated

 

[crabjoe]

Was the breaker sized correctly for your unit? Have you looked at the capacitor to see if they're good? How about amps needed to start her running?

If your breaker is undersized and your capacitor is going bad ... it could now start tripping the breaker where it was fine before..

 

[Paul.le]

I even tried with new capacitor.

 

[user_12345a]

does it trip right away or take a few seconds?

could be a dead short in the unit if the former.

 

[Paul.le]

In couple seconds

 

[beenthere]

Do you have a multimeter, and know how to use it.

 

[roughneck]

Was the old capacitor faulty? What's the compressor ohm out to? Is their polarity to ground?

 

[crabjoe]

If you ain't got the tools, you'll be guessing where the problem might be. And if you don't want to invest in the tools, your next ... at least my next guess ... part swap would be the breaker... Just make sure it's the proper size... Your problem might be as simple as wrong breaker being installed and now that it's gotten weak, it can't handle the start up draw.

 

[user_12345a]

get a multi-meter and ohm out the outdoor unit, especially between line voltage and ground.

unlikely to be the breaker, it's probably doing it's job.

 

[beenthere]

get a multi-meter and ohm out the outdoor unit, especially between line voltage and ground.

unlikely to be the breaker, it's probably doing it's job.

Never use a multimeter to try and ohm out line voltage to ground. If your lucky, the fuse in the meter will blow. If your not lucky, the meter may be ruined, and older meters can catch fire.