Condenser Tripping Breaker When Air Turned On


Old 11-05-17, 02:04 PM
Thread Starter
Join Date: Feb 2012
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
Condenser Tripping Breaker When Air Turned On

Hey Guys -

Need some advice, please. We haven't had air for 24 hours upstairs due to issue. Units being replaced in a few days, but trying to get it working for cheap until then.

Our upstairs unit is a 2 ton Rheem split where the AC / furnace is in the attic and condenser is outside. There is a single breaker going to another breaker box which has two breakers with one going to downstairs unit and other to condenser. The air upstairs wasn't cold, then all of a sudden we had no air at all. I found out that the main breaker (for both units) had tripped and I couldn't turn back on. I eventually turned off the breaker just for the condenser and then it came back on and we at least then had downstairs air.

I've checked out the condenser as well as I know how and learned a bit about them in the process. With the air turned off at the thermostat, I can power the condenser back on and the fan starts to turn. However, every ~20 seconds, there's somewhat of a surge noise. If the upstairs thermostat is turned on, though; the breaker is tripped. With the thermostat on and breaker off, the contactor makes a humming noise. I checked to see if it was stuck and do not believe it to be as with the thermostat off and breaker on, it's in the outward position. I cleaned around all terminals close to the contactor on the condenser and didn't see any wires that could be grounding it out or causing a short. No burn marks, either. I also cleaned the unit a bit - still the issue persists.

The attached pictures include the panel I cleaned cobwebs from and checked for grounding / burnt wires. Here is a link to a video of the unit running (with thermostat turned off.) You can hear the noise I mentioned at 6 and 30 seconds in.

Any suggestions? Thanks!
Attached Images   
Sponsored Links
Old 11-05-17, 03:25 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,729
Received 346 Votes on 324 Posts
With the air turned off at the thermostat, I can power the condenser back on and the fan starts to turn.
How about when the thermostat is calling for cooling. Holding the contactor in is only a momentary check. If the condensor fans runs fine but the compressor cycles..... you may have a defective start/run capacitor for the compressor and maybe for the fan if it's a combo unit. Plenty of threads here on capacitor problems.

If it's being replaced in a few days it may not even be worth the bother or cost to replace the cap.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes
Ask a Question
Question Title:
Your question will be posted in: