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Posted: 7/4/2015 7:01:11 PM EST
Alright, my two ton Trane central A/C was installed in May 2007. Almost every summer since then, I've had various issues with it, nearly exclusively with the condenser unit outside. I have a bit of a bad memory when it comes to this particular subject as I wasn't always the one that was home when it was replaced/repaired, and I have zero electrical knowledge, so bear with me.

For the last two to three weeks, the breaker that controls the condenser has been getting tripped. Sometimes it's three or four days in between trips, sometimes it does it multiple times in a day. I had service techs out twice, once about two weeks ago when it did it the first time and once yesterday. The guy that came out first said everything was fine and there was nothing wrong, didn't charge me for the visit and left. The one yesterday checked everything again and said the same thing, didn't charge me, and left.

Fast forward to today, I woke up and the A/C was set on 74 degrees, but it was 77 in the house. I went out to flip the breaker off and back on, and it wouldn't flip back on. I took the cover off the circuit breaker, flipped the main, removed the (presumably bad) breaker and drove out to Lowes to replace it. Got a new one, came home, installed it, flipped the main back on and it did the same shit the old one did (tripped immediately and wouldn't even click on then trip, just stayed tripped). Called my buddy who is more knowledgeable with A/C and electrical stuff than I am as he just re-did the majority of his house and had done some of those things himself. While going through things top to bottom, it was discovered that when the A/C was installed, they put a 30-amp unit in and ran it off of a 20-amp breaker. Suddenly explains why every summer when it gets really hot, it freezes up and over-works the pump that drains water from the air handler if you turn it down past 74 degrees. Also why almost every summer, there is some sort of issue with the A/C itself and parts going bad or stuff needing tune ups.

If that's the culprit, now the problem is I can't find any writing on the insulation for those wires that go into the breaker (or out of the disconnect on the exterior of the house behind the condenser unit on the concrete patio) that tells me what gauge the wiring is. I don't know if I can replace it with a 30-amp breaker without melting wires and running a fire risk, so I'm basically stuck until tomorrow when I pay an astronomical service charge for an electrician to tell me whether this will be a $15 repair cost or an unknown repair cost (removing and re-wiring for the air conditioner itself with the proper gauge wire for that size breaker/power load)...

Anybody with electrical knowledge, does that make sense to you or should I be looking at other stuff too?
Link Posted: 7/4/2015 7:03:44 PM EST
[#1]
Link Posted: 7/4/2015 7:23:52 PM EST
[#2]
I was really hoping I could find out what gauge that wiring was tonight so I could run to Lowes real quick and get another breaker of the proper size if it's the correct gauge wiring before they closed at 8:00pm, but I couldn't see very well and couldn't get behind the condenser to get to the conduit and unscrew it from the bottom of the disconnect box outside.

If it isn't the right wiring, I shudder to think of what that will cost to repair. I rarely look at that stuff (unless it breaks), and I should have noticed it before now, but how do you not check that when you install a whole new cooling system?
Link Posted: 7/4/2015 7:28:53 PM EST
[#3]
Check and see what size breaker is in the main electrical panel on your house.

Probably better way to see what size wire you have running out there also.
Link Posted: 7/4/2015 7:33:42 PM EST
[#4]
does the breaker feel warm when the unit has been running?  if so, it shouldnt and needs to be replaced
Link Posted: 7/4/2015 7:40:22 PM EST
[#5]
I removed the old breaker and took it with me to Lowes earlier this afternoon and got a replacement, installed the new one and as soon as I put power to it, it tripped itself. Wouldn't even turn on at all, it was either off or tripped. The 20-amp breaker that was in there has been installed for years as far as I can remember (don't recall it ever being replaced by any service techs, I normally stand out there and watch them so I can remember what they did for the future). I'm guessing, with my luck, that the wiring will need to be replaced because whoever did this obviously didn't give enough of a shit to do it CORRECTLY the first time...

I couldn't get to the top of the conduit that went into the disconnect on the exterior garage wall to unscrew it from the box and see if I could find any type of writing or labeling that indicated what gauge thickness that wire was. Nothing in the main circuit breaker inside the garage either.
Link Posted: 7/4/2015 7:45:17 PM EST
[#6]
Is the wire running from the breaker solid or stranded? If solid it's likely 10 wire which is fine on 30A
Link Posted: 7/4/2015 7:49:21 PM EST
[#7]
I believe solid. At this point, having it figured out tonight doesn't matter anyways because the stores are closed and I couldn't get a new breaker if I wanted to.
Link Posted: 7/4/2015 7:49:24 PM EST
[#8]
A 30 amp breaker needs 10 gauge wire.  Buy a small piece and compare it.  If it's  12gauge you can only install a 20 amp breaker
Link Posted: 7/4/2015 7:52:35 PM EST
[#9]
Yeah, that's what I'm hoping it has instead of the 12ga wiring... but that would be my house. Nothing in here was done the way it was supposed to be.
Link Posted: 7/4/2015 7:58:44 PM EST
[#10]
Yea you have 10 gauge wire. If your worried it's shorted in the wire, turn off the breaker, go into your condenser and disconnect the high voltage wires as well as the ground wire. There will be two high voltage wires and one ground. Make sure they aren't touching anything (capping with a wire nut would be safe) and turn on the breaker. If it trips your wires have a short. If not, connect back to the unit and turn back on. If it trips this time the short is in the conxenser.
Link Posted: 7/4/2015 8:10:07 PM EST
[#11]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


I was really hoping I could find out what gauge that wiring was tonight so I could run to Lowes real quick and get another breaker of the proper size if it's the correct gauge wiring before they closed at 8:00pm, but I couldn't see very well and couldn't get behind the condenser to get to the conduit and unscrew it from the bottom of the disconnect box outside.



If it isn't the right wiring, I shudder to think of what that will cost to repair. I rarely look at that stuff (unless it breaks), and I should have noticed it before now, but how do you not check that when you install a whole new cooling system?
View Quote
Get a wire gauge at Lowes and measure it

 
Link Posted: 7/4/2015 9:13:40 PM EST
[#12]
The inside of the fuse box mounted on the exterior of the house leading to the compressor melted last year. Besides replacing the fuse box I replaced the capacitor (looks like a battery) and the switching unit inside the compressor access panel. Good to go after that.

I say this because the wire gauge issue may be leading you off in the wrong direction. The two parts mentioned was something like $15 all together. Replace those and see what that does.
Link Posted: 7/4/2015 9:56:09 PM EST
[#13]
You have a dead short, most likely in the compressor windings. How you check it is pull the 3 wires off of the comp and ohm it out the terminals directly to the suction line. if you get anything other than infinity you found your problem.
Link Posted: 7/4/2015 10:11:24 PM EST
[#14]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


You have a dead short, most likely in the compressor windings. How you check it is pull the 3 wires off of the comp and ohm it out the terminals directly to the suction line. if you get anything other than infinity you found your problem.
View Quote
Winner winner, chicken dinner.



I was going to suggest you pull out the multimeter and measure the resistance on your wiring.



 
Link Posted: 7/4/2015 10:17:59 PM EST
[#15]
disconnect the crankcase heater and see if you can reset the breaker
Link Posted: 7/4/2015 10:24:13 PM EST
[#16]
Our breaker did this when the compressor locked up. If you flipped the beaker on with the AC on the breaker tripped instantly. If you turned it on with the AC off, as soon as the AC was turned on it flipped.
Link Posted: 7/4/2015 10:36:17 PM EST
[#17]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Winner winner, chicken dinner.

I was going to suggest you pull out the multimeter and measure the resistance on your wiring.
 
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
You have a dead short, most likely in the compressor windings. How you check it is pull the 3 wires off of the comp and ohm it out the terminals directly to the suction line. if you get anything other than infinity you found your problem.
Winner winner, chicken dinner.

I was going to suggest you pull out the multimeter and measure the resistance on your wiring.
 

thats what was wrong withmy rheem 5 ton, you tube it,
multi meter will show if the saftey in the comp kicked out.
i read that sometimes a whack with a hammer can reset
the safety, not mine.found a new scroll comp for $700,
online a/c supply, had a local tech install for $400.beat the
$6000 i was quoted by a ruthless a/c contractor. 2 ton comps
are way cheaper.
Link Posted: 7/4/2015 10:51:09 PM EST
[#18]

Discussion ForumsJump to Quoted PostQuote History
Quoted:





thats what was wrong withmy rheem 5 ton, you tube it,

multi meter will show if the saftey in the comp kicked out.

i read that sometimes a whack with a hammer can reset

the safety, not mine.found a new scroll comp for $700,

online a/c supply, had a local tech install for $400.beat the

$6000 i was quoted by a ruthless a/c contractor. 2 ton comps

are way cheaper.

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:



Quoted:


Quoted:

You have a dead short, most likely in the compressor windings. How you check it is pull the 3 wires off of the comp and ohm it out the terminals directly to the suction line. if you get anything other than infinity you found your problem.
Winner winner, chicken dinner.



I was going to suggest you pull out the multimeter and measure the resistance on your wiring.

 


thats what was wrong withmy rheem 5 ton, you tube it,

multi meter will show if the saftey in the comp kicked out.

i read that sometimes a whack with a hammer can reset

the safety, not mine.found a new scroll comp for $700,

online a/c supply, had a local tech install for $400.beat the

$6000 i was quoted by a ruthless a/c contractor. 2 ton comps

are way cheaper.

No such thing as a cheap traine comp, especially if it uses suction and discharge fittings.

 
Link Posted: 7/5/2015 12:14:03 AM EST
[#19]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Our breaker did this when the compressor locked up. If you flipped the beaker on with the AC on the breaker tripped instantly. If you turned it on with the AC off, as soon as the AC was turned on it flipped.
View Quote


When I tried all this earlier, the thermostat was turned off already
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