Do it Yourself: Re: [DIY] AC tripping circuit breakers

09 June 2014

Re: [DIY] AC tripping circuit breakers

Odds are against the breaker (unless it is a Zinsco). Could be a capacitor or the compressor out (both will need a qualified repairman). However, the 1st thing to try is to clean the coils on the outside unit. Use a garden hose with a nozzle or a car wash wand which you can put soap into. Be careful not to bend the fins. Spray straight in, not at an angle. Dirty coils will build up head pressure in the compressor and cause it to pull excess amperage.

On 6/9/2014 12:04 AM, bigmikechen@yahoo.com [DoIt_Yourself] wrote:

Our AC has been working fine for a while (the furnace motor had to be replaced a year ago, the unit is 14 years old). However, this afternoon it stopped working. The fan would blow but when you turned it on at the thermostat, the compressor wouldn't come on. I went to the main fuse box and saw that the breakers had flipped.

I reset them and also checked the AC service disconnect, which was fine. After resetting the breakers, the AC ran fine for about 15 minutes before crapping out again. I checked outside and it was the same issue. I waited about an hour, then repeated the process to the same effect.

It was a pretty hot day in the Bay Area (mid 90s), so I waited for it to cool down in the evening. I did that, reset the breakers, and tested again. It functioned off and on per normal degree increments over the course of 45 minutes. Then I really tested it by forcing it down 5 degrees. So cumulatively, it ran for about 40 minutes including a few 2-3 minute breaks during this time before the breakers tripped again.

It sounds like a lot of people fixed this by replacing the breakers. I bought a replacement part but I'm not totally comfortable with electrical stuff so I'm waiting for some help to drop by tomorrow. Any other areas I should troubleshoot in the meantime or are all signs pointing to the breaker?

Thanks!

Mike