AC trips the main breaker after about an hour

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TomP
Posts: 83
Joined: Sun Jan 31, 2010 2:07 pm

AC trips the main breaker after about an hour

Post by TomP »

The overhead/house AC unit will trip the main (green) breaker on the breaker box after about 30-60 mins of running it on medium fan at about 80% max cold.

Nothing else is running in the rig except for the frig.

Any ideas?
1995 Born Free 24' Rear Side Bed
randallrae
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Joined: Wed May 22, 2013 7:30 pm

Re: AC trips the main breaker after about an hour

Post by randallrae »

You should check incoming voltage , as voltage goes down current goes up . If the supply voltage is 120 volts +or_ 8% , you should measure incoming current .
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oliverpsmile
Posts: 271
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Re: AC trips the main breaker after about an hour

Post by oliverpsmile »

After checking the voltage and the amps, it would be a good idea to replace the breaker. The breakers, after years of service, get little corroded (contacts and terminal points) and start overheating.
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bcope01
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Re: AC trips the main breaker after about an hour

Post by bcope01 »

Agree with Oliver. The more often a breaker is tripped, the weaker it becomes. I'd try replacing the breaker first.

Bill
Barb & Bill
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TomP
Posts: 83
Joined: Sun Jan 31, 2010 2:07 pm

Re: AC trips the main breaker after about an hour

Post by TomP »

It's the main breaker that trips, not the A/C breaker. Obviously, it's a 30AMP breaker. I hookup up a clamp ammeter to the wire feeding the breaker and it peaked at 18AMPs but otherwise ran at about 16AMPs. I did notice that the wire was hot to the touch.

I will look into getting a new breaker. No harm in that.

Thanks!
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mike&linda
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Re: AC trips the main breaker after about an hour

Post by mike&linda »

If your wire going to the breaker is hot this may indicate a poor connection. Try tightening all the terminal screws on all of the breakers this may help with your problem. Mike
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whemme
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Re: AC trips the main breaker after about an hour

Post by whemme »

My opinion is that your 30 amp circuit breaker has developed enough resistance between its contacts that the 16.3 amps for the A/C is generating enough heat to trip that circuit breaker. Sufficient heat buildup is what causes a circuit breaker to trip. That heat at the internal breaker contacts is conducted to the attaching wires via the breaker screw terminals making the wires hot also. My opinion is that that 30 amp breaker is worn out and should be replaced.
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TomP
Posts: 83
Joined: Sun Jan 31, 2010 2:07 pm

Re: AC trips the main breaker after about an hour

Post by TomP »

is there a standard type of breaker? how would i know if the one i see on amazon will work? spec number or something?

This one looks nearly identical except for the brand:

https://www.amazon.com/Square-Schneider ... it+breaker
1995 Born Free 24' Rear Side Bed
oliverpsmile
Posts: 271
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Re: AC trips the main breaker after about an hour

Post by oliverpsmile »

Most likely Squire D. If you bring the old one to Home Depot, it would be very easy to select one.
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TomP
Posts: 83
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Re: AC trips the main breaker after about an hour

Post by TomP »

It's a westinghouse breaker. I'll see what they have at HD.

Thanks for all the advice.
1995 Born Free 24' Rear Side Bed
Kevin Mason

Re: AC trips the main breaker after about an hour

Post by Kevin Mason »

Agree with Mike, check your terminal screw connections on electrical bar. They have a tendency to work loose and cause wiring to get hot and melt. Poor conection equals higher amperage...
TomP
Posts: 83
Joined: Sun Jan 31, 2010 2:07 pm

Re: AC trips the main breaker after about an hour

Post by TomP »

Everything was tight. I'm going to make it to HD soon for a breaker.
1995 Born Free 24' Rear Side Bed
TomP
Posts: 83
Joined: Sun Jan 31, 2010 2:07 pm

Re: AC trips the main breaker after about an hour

Post by TomP »

Since replacing the breaker, I've had no issues. FYI.
1995 Born Free 24' Rear Side Bed
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