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#211478 - 10/18/13 12:27 PM new breaker box blew out my a/c - who pays?
aggillator Offline
New Member

Registered: 10/17/13
Posts: 3
Loc: TX, US
Hi Everyone,

I had an electrician out a couple months ago to install a new breaker box. Just recently, my air conditioner stopped working and I had an A/C guy out who diagnosed the issue as a burnt out compressor. He said that the compressor was supposed to only have 40 watts(?) and the fuse that it was connected to was delivering 50. Is this the electrician's responsibility for not checking that the fuse was compatible with my air conditioning unit?

Thanks for the advice,
Adam

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#211479 - 10/18/13 12:46 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Good Afternoon:
I can explain this briefly:
The manufacturers nameplate on the HVAC CU has a minimum and maximum amperage listed for that specific model.

The maximum overcurrent (fuse or circuit breaker) is not to be exceeded. Also note that some units specify 'fuses only'.

More than likely, when your panel was changed, the electrician installed new circuit breakers sized to match the existing ones in the old panel.

You mention 'fuse'; but do not mention the circuit breaker that feeds the circuit from the panel.
_________________________
John

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#211480 - 10/18/13 12:53 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
I was going to lock this thread, but I will leave it up for a while.
_________________________
John

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#211482 - 10/18/13 02:48 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
twh Offline
Member

Registered: 03/11/04
Posts: 898
Loc: Regina, Sask.
Oversized overcurrent doesn't burn out motors and overcurrent protection doesn't protect against overload. Overcurrent protection on a motor (or compressor) protects the wires if there is a failure on the circuit. The overcurrent will trip if the motor is locked but the motor has to be locked first.

I call bs on the oversized overcurrent burning out the motor. I say the locked compressor tripped the breaker. It's the A/C guy's fault.

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#211483 - 10/18/13 05:21 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
aggillator Offline
New Member

Registered: 10/17/13
Posts: 3
Loc: TX, US
The A/C was not working first. So that's when we called the A/C guy. We already had the A/C before the breaker box was installed. The A/C guy didn't do anything, he just ruled out all the other things and found a dead compressor.

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#211484 - 10/18/13 06:39 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
JoeTestingEngr Offline
Member

Registered: 11/04/05
Posts: 786
Loc: Chicago, Il.
That's quite a smart AC guy who knows what took out that compressor. He must have a BS degree. I had a guy BS my aunt that way once. He very eloquently defended his BS actions while he refunded her $$$.
Joe

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#211485 - 10/18/13 07:03 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
twh Offline
Member

Registered: 03/11/04
Posts: 898
Loc: Regina, Sask.
The solution was to replace the compressor so the compressor must have been the only problem.

If the A/C guy had to replace something else and the compressor, there might be a chance a smaller breaker could have saved the compressor if the "something else" might have caused the compressor to stall. If the something else just caused the compressor to overload, its internal overload protection should have handled that. Breakers don't protect against overload.

The A/C guy said the reason the compressor failed is that the breaker was too big, I have to wonder what motivated that. I don't think that idea will fly.

Sometimes compressors fail.

Still the breaker should be properly sized to protect the conductors. You might be able to stick the electrician with that cost. He relied on the guy before him to properly size the breaker. Maybe you can get the original installer to pay for the breaker.

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#211486 - 10/19/13 07:07 AM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
twh Offline
Member

Registered: 03/11/04
Posts: 898
Loc: Regina, Sask.
Oh, and about the title to the thread "new breaker box blew out my a/c", that sounds really ... uninformed. The "who pays?" part makes it sound wilful.

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#211487 - 10/19/13 06:48 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Hi there,
Did the A/C guy actually state HOW the compressor was faulty?
Usually, the guy would need to put a megohm meter on it to check the winding resistances to ground and the actual winding resistances themselves, did he provide you with any test results after coming to that conclusion?

It isn't unusual for compressors to fail because of a voltage spike, no CB or fuse will ever protect against something like that, I've seen this happen quite a few times
You didn't state how old the A/C unit was in your OP?

I would find it pretty tenuous to blame an A/C unit failing because of a panel upgrade.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#211490 - 10/19/13 08:02 PM Re: new breaker box blew out my a/c - who pays? [Re: aggillator]
NORCAL Offline
Member

Registered: 09/25/02
Posts: 807
The A/C tech has to blame someone, the compressor has overloads, the fuses or circuit breaker is just for short circuit protection.

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