afci breaker tripped today after 10 months

[jimmy_mcquade]

Hi all,

i bought a 6 year old house last august and the electrical system has given no problems until today.
a bedroom cutler hammer afci breaker tripped today while i was at work and i'm trying to understand why.

i'm in industrial electrical work so the home aspect is new to me.
what would cause the breaker to trip in the middle of the day while no one was at home?
i plan to to trace the circuit out this weekend, but should i be worried until then?
should i turn the circuit off until i check the receptacles and lights or what ever the circuit is connected to?

thanks in advance,
jimmy

 

[Little Bill]

Hi all,

i bought a 6 year old house last august and the electrical system has given no problems until today.
a bedroom cutler hammer afci breaker tripped today while i was at work and i'm trying to understand why.

i'm in industrial electrical work so the home aspect is new to me.
what would cause the breaker to trip in the middle of the day while no one was at home?
i plan to to trace the circuit out this weekend, but should i be worried until then?
should i turn the circuit off until i check the receptacles and lights or what ever the circuit is connected to?

thanks in advance,
jimmy

What was plugged in to the circuit when it tripped? Was there anything that was added recently to the circuit?

I do know this from personal experience. Lightning storms can cause them to trip, even take them out.

Were you able to reset it?

 

[templdl]

What was plugged in to the circuit when it tripped? Was there anything that was added recently to the circuit?

I do know this from personal experience. Lightning storms can cause them to trip, even take them out.

Were you able to reset it?

I agree that this would be a good place to start. With my knowledge and experience of the AFCI they rely on their 30ma GF sensitivity a lot as it is not unusual for a line to arc to ground and be picked up by the GF. Nuisance tripping can be caused by a EGC coming into contact with the grounded neutral conductor of a duplex outlet. I was a beta site for the AFCIs a few months prior to their being released to to market. One of my breakers tripped a few months after installation. After ringing out the circuit I discovered that when the electrician wire the housed when he pushed a convenience outlet Bach into a 4x4 box crammed with #12 wire the EGC folded up and against the neutral. Now the EGC was sharing the neutral current which the AFCI interpreted as a ground fault. I had the AFCIs installed since about 1998 and I haven't had and issues since.
If the cause isn't identified I would proceed by disconnecting all loads entirely. With the AFCI off remove it and remove the line, neutral from the breaker and EGC. Take your multimeter and check to see if there is any continuity between the neutral and EGC which you are looking for an open circuit. If you do measure some level of continuity that's when you have to ring of the circuit.

 

[jimmy_mcquade]

thanks for the replies.

the loads are tv, clock, transformer power supply, cell phone charger, the same stuff thats been there
for the last 10 months.

yes, i was able to reset and test the breaker and it turns on / off ok.

i do know that it rained here earlier today, don't know about a storm though.
i hope that is what did it.

the thing is, there is no electrical prints.
the guy wired the house goffy as far as i'm concerned.
there are receptacles in the living room, bedrooms, hall, and who knows what else, all tied to this breaker.
i'll have to move all the furniture on the walls just to plug in a receptacle tester with indicator lights.

i'm beginning to like dad's wiring method to his house more and more.
1 room, 1 breaker, 12 ga wire, 20 amp switches and receptacles.
dedicated circuits where required, AND everything documented on the panel and with prints.

if anyone else has suggestions, please comment.

thanks again,
jimmy

 

[Little Bill]

the loads are tv, clock, transformer power supply, cell phone charger, the same stuff thats been there
for the last 10 months.

My top three suspects would be two from the list, and the lightning I mentioned earlier.

I've heard on more than one occasion of cell phone chargers tripping them.
I know you said the things have been there for a while, but they can go bad over time for various reasons.

If you're really interested in finding the culprit, I would start by leaving the power supply off of the circuit for a while. If it holds, then leave off the phone charger and see if that trips. Then if that holds, try the other things on the circuit, one at a time.

If it's lightning, take note of when there is a storm, then check the AFCI.

Since the AFCI reset ok, I would not think you had a neutral-ground fault anywhere.

 

[jimmy_mcquade]

Little Bill,

thanks for the reply.

regards,
jimmy