Trouble shooting afi circuit

[jerrygar]

I am working on correcting a job that was not done by me. Most problems have been solved, one remains.

I have a 15 amp afi circuit for lighting (and plugs) in the dining room and bedroom. When I turn on either of the lights the afi trips. I replaced it with a new one, same result. I put in a regular breaker and it holds.

I find it odd that either light, on separate switch legs, trips the afi. Any advice on how to most efficiently track this down?

Jerry

 

[electricalperson]

I am working on correcting a job that was not done by me. Most problems have been solved, one remains.

I have a 15 amp afi circuit for lighting (and plugs) in the dining room and bedroom. When I turn on either of the lights the afi trips. I replaced it with a new one, same result. I put in a regular breaker and it holds.

I find it odd that either light, on separate switch legs, trips the afi. Any advice on how to most efficiently track this down?

Jerry

i would megger the circuit (remove electronic loads and lightbulbs) that might help find the problem

 

[Dennis Alwon]

First off I hope this is old construction with the dining room and bedroom on the same circuit.

Secondly I would change bulbs-- different brand and see what happens. I have known bulbs to cause this problem. The other probability is you have a neutral to ground short somewhere.

If you plug something into the receptacles does the circuit trip also????

 

[76nemo]

I am working on correcting a job that was not done by me. Most problems have been solved, one remains.

I have a 15 amp afi circuit for lighting (and plugs) in the dining room and bedroom. When I turn on either of the lights the afi trips. I replaced it with a new one, same result. I put in a regular breaker and it holds.

I find it odd that either light, on separate switch legs, trips the afi. Any advice on how to most efficiently track this down?

Jerry

Is this a new install, or been happening for awhile???

 

[electricalperson]

check the wiring at the switches to see if there is another circuit neutral tied to the neutral conductors from the afci circuit

 

[mdshunk]

It's pretty easy to get a wire pinched (possibly a neutral) between the cover and the box when putting the junction box cover on a recessed can after wiring it up. Just a thought. I'd probably take the cable off all the terminals in the panel, turn the switch(s) on, then ring out the cable neutral to ground. First with an ohm meter, then with a megger.

 

[ptonsparky]

Make sure the neutral is not tied in with another branch circuit. May or may not be a MWBC. You may have to remove all the neutrals at the bar & ohm them out for continuity. May be just an oops or poor practice.

 

[CHWflorida]

In my experience, out of hundreds of new houses that i have hot checked, 9 out of 10 times it is a simple case of the egc touching the grounded conductor (when wired in romex). In second place, for most common problem, is a shared neutral. I usually look in three way switch boxes if there are any on that circuit. In third place is the one that stares you right in the face but sometimes the last place I look, which is the grounded conductor mixed up with another in the panel (happens alot with mc). I usually (and I think it's wisest) start in the panel, like others have mentioned, and just test for continuity between ground and neutral and then work from there.

 

[CHWflorida]

I find it odd that either light, on separate switch legs, trips the afi. Any advice on how to most efficiently track this down?

Jerry

This most likely has to do with putting a load on the circuit. It's not necessarily either of those switchlegs that's the problem. Those are probably the only lights on that circuit, right?.

 

[MagnoliaElec]

Another thought is if the romex is striped with a cut across the sheath the neutral wires insulation can be nicked and when the box is made up a ground can lay in that nicked section causing your Arc to trip.