Afci breaker tripping

Status
Not open for further replies.
I have just completed trim out on power (receptacle)circuits in a Residents. All breakers hold. As soon as any load is present on ANY afci circuit one of the afci breakers trips. The tripping breaker is circ. LVC1 however any load on any other circuit,including LVC1 and excluding gfcis and standard breakers, will cause this fault. I have isolated every device that appears to be on circ LVC1 and can find no loose connection, neutral to ground contacts or any other issues. The thing that is really getting me is what effect would a load have being on a completely different afci circuit?? Two neutrals tied together from two different afci circuits?? Can't find any but that's all I can think of..... I'm stumped.... Thoughts?
Also no lighting circs have been energized so no issues with led ... Yet....
 

bobbymari

Senior Member
Location
los angeles ca
Yes the load is when the fault would occur if neutrals are crossed on a different circuit.
You mentioned no light trims yet.
Any bath fan/light combos, fed through switch boxes etc..
Need to check those as well not just receptacles.
Only ask cause we found a shared neutral issue in a heat fan light combo where the heater had its own circuit and neutrals were reversed.
Also check panel just to be certain the correct neutrals go to the correct afci breakers. Sounds obvious I know, but it happens
 

JFletcher

Senior Member
Location
Williamsburg, VA
Make sure the neutral of the AFCI is connected to the neutral bar and the branch circuit neutral is connected to the proper breaker. NO shared or crossed neutrals. No MWBC.

This. CA is on the 2014 NEC, yes? So you have lots of AFCI breakers... rules out damaged runs causing your problems.

Out of curiosity, what is your load?

and welcome to the forum.
 
California 2011nec cycle. I inspected the panel thoroughly for crossed neutrals and found none however I will double check. All fans are fan only and no multi wire branch circuits. So a crossed neutral in the field, say LVC4 and LVC5 could effect and cause to fault LVC1?? Or LVC1 must be involved in the cross up in order to be effected??? And if the latter were the case why only one breaker trips and not both afci's involved?
I already love this forum!
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
California is on the 2013 Calif electrical code which to my knowledge is base almost in its entirety from the 2011 NEC.

in 2017 we will be based on the 2014 NEC.
 
All circuits , from this panel,are afci excluding bathrooms and kitchen which are gfci. Air handling unit is on standard breaker and none of those loads cause a trip. The load that tripped it initially was a shop vac connected to LVC7 I then took it around to all circuits and same thing. Then I did the same with a dewalt battery charger and same , LVC1 trips. All of this after I inspected all terminations and devices on LVC1. I also changed out the offending breaker in hopes that I was defective but no such luck. And by no lighting loads I mean I have not energized any of those breakers yet but they are also afci.
 

bobbymari

Senior Member
Location
los angeles ca
All circuits , from this panel,are afci excluding bathrooms and kitchen which are gfci. Air handling unit is on standard breaker and none of those loads cause a trip. The load that tripped it initially was a shop vac connected to LVC7 I then took it around to all circuits and same thing. Then I did the same with a dewalt battery charger and same , LVC1 trips. All of this after I inspected all terminations and devices on LVC1. I also changed out the offending breaker in hopes that I was defective but no such luck. And by no lighting loads I mean I have not energized any of those breakers yet but they are also afci.

A neutral to ground issue would trip instantly even without a load. Its more than likely going to be a neutral mixup somewhere
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
we will de energize , remove the MBJ , ring out each neutral to ground and to the N bar as we remove each neutral one at @ time

~RJ~
 

kwired

Electron manager
Location
NE Nebraska
A neutral to ground issue would trip instantly even without a load. Its more than likely going to be a neutral mixup somewhere
That depends. GFCI's do inject a signal to detect N-G fault even with no load, IDK if AFCI's do this or not. If they don't then current is needed before they will trip.

I do believe there is a good possiblility of a N-G fault on the circuit that always trips. Seems that N-G fault on the circuit in question is a parallel path for feeder neutral current and is why it trips even when no load is specifically connected to that circuit.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
A neutral to ground issue would trip instantly even without a load. Its more than likely going to be a neutral mixup somewhere
A GFCI receptacle will trip without load on an EGC to neutral connection since it contains a signal injector circuit.
An AFCI breaker with GF protection will not have that additional component.
 

JFletcher

Senior Member
Location
Williamsburg, VA
A neutral to ground issue would trip instantly even without a load. Its more than likely going to be a neutral mixup somewhere

Maybe not all AFCI would trip with such a fault. I believe SqD will hold with a neutral->ground fault provided there is zero load (not even a GFCI light on it). Hopefully the OP reports back with the problem(s) he found
 

bobbymari

Senior Member
Location
los angeles ca
Maybe not all AFCI would trip with such a fault. I believe SqD will hold with a neutral->ground fault provided there is zero load (not even a GFCI light on it). Hopefully the OP reports back with the problem(s) he found

Murray is what we use in residential and a neutral to ground issue trips instantly with no load.
Not sure of square d but Ill take your word for it, after I check..haha
 
Ok , problem solved..... I tracked down a receptacle way out in left field that was incorporated into LVC1. the bare ground wire was not making contact (so no tone on continuity test)but it was close enough to the neutral terminals I guess that when a load was applied it arced N-G.??. As soon as I pulled that puppie out circuit holds.. Taped her up and holding for 30 min now... Still a little puzzled how a load on another circuit would cause that arc but I'll take it. Thanks for all the input guys !!
 

10fords

Member
Location
California
Ok , problem solved..... I tracked down a receptacle way out in left field that was incorporated into LVC1. the bare ground wire was not making contact (so no tone on continuity test)but it was close enough to the neutral terminals I guess that when a load was applied it arced N-G.??. As soon as I pulled that puppie out circuit holds.. Taped her up and holding for 30 min now... Still a little puzzled how a load on another circuit would cause that arc but I'll take it. Thanks for all the input guys !!
Had the exact same thing happen only with homeline breakers. Square D (Schneider) assured me that it couldn't have happened that way and I must have crosswired a neutral. In my case only afci's on the same phase as the one that had the neutral to ground arc would trip and it took at least a 200 watt load. It cost me 2 days lost labor and some sheetrock repair to correct the flaws in this BS afci experiment:rant:
 

kwired

Electron manager
Location
NE Nebraska
Had the exact same thing happen only with homeline breakers. Square D (Schneider) assured me that it couldn't have happened that way and I must have crosswired a neutral. In my case only afci's on the same phase as the one that had the neutral to ground arc would trip and it took at least a 200 watt load. It cost me 2 days lost labor and some sheetrock repair to correct the flaws in this BS afci experiment:rant:
It was similar situation to having an actual crosswire if neutral was touching the EGC somewhere. If it was like VTW had with it just running extremely close to a terminal, maybe it does make contact some of the time, slight temperature changes may determine when it makes contact. A megger hopefully would indicate trouble here.

As much as I don't agree with AFCI requirements this would have been an issue with a GFCI protected circuit as well, finding the problem would similar approach.


Still puzzles me why OP's problem effected more then just the AFCI on the branch circuit where the mentioned problem was, his problems may not be over yet.
 
Status
Not open for further replies.
Top