Arc Faults on old circuits

[User Name]

Hey fellas, so code 210.12(D) basically says if I modify, replace, or extend a branch circuit (dwelling) I have to install arc fault protection. With the exception that if its under 6' its not required, basically so we can just change out a panel or fuse box without racking up a ton in cost.

So what happens when I move the breaker panel 20' away to make way for an addition on this dwelling, fully prepared to install arc faults because I know I need them, and they don't work. First 3 circuits I attempted the afci breakers (SqD) they all tripped. I'm connecting new 12/2 w/g romex to 1970's 12/2 w/g romex so it's not like its knob and tube at least. And even tried an existing circuit that reached the new panel and won't hold the afci. I can't tear apart every light and outlet in this place to hunt down a ghost I may never find. Is there anything else I could try here that I'm missing or does a guy just kind of say hey at least I tried.

There is one saving grace to this is a lot of the house is going to get remodeled so I'm hoping the opportunity to install new circuits from start to finish, then I know my afci will work... But some of it might not....

 

[Another C10]

fully prepared to install arc faults

I suppose you could install Arc Fault devices but that sort of defeats the point of protecting the wiring, Another angle is disconnect a circuit at mid points having trouble and after connection by connection weed out the fault, could very well be a neutral touching a ground in a box somewhere, I always tape around the terminals of devices for better isolation.

Good luck.

 

[George Stolz]

Sounds like a sound reason to include this caveat in the bid: "Excludes troubleshooting of branch circuits connected to AFCI circuits if required. Such troubleshooting and repair to be completed on a time and materials basis after contract work is completed."

Oof.

 

[tortuga]

First 3 circuits I attempted the afci breakers (SqD) they all tripped.

What kinda trip did the breaker tell you it was?
I have had the exact same problem countless times lately, I first test continuity from each circuits neutral to the ground bar before I land it on the AFCI.
If you have continuity you have a parallel neutral path, which was never allowed by code anyways.
Often its someone just wire-nutted all the neutrals together in a big 4 gang switch box, not that big of a deal to fix.
One I tracked down recently was a wire nut in a kitchen light box that looked like Another C10's profile photo there.
I also carry a few GFCI breakers to swap in for testing, if the GFCI trips Ill take that more seriously.

 

[User Name]

What kinda trip did the breaker tell you it was?
I have had the exact same problem countless times lately, I first test continuity from each circuits neutral to the ground bar before I land it on the AFCI.
If you have continuity you have a parallel neutral path, which was never allowed by code anyways.
Often its someone just wire-nutted all the neutrals together in a big 4 gang switch box, not that big of a deal to fix.
One I tracked down recently was a wire nut in a kitchen light box that looked like Another C10's profile photo there.
I also carry a few GFCI breakers to swap in for testing, if the GFCI trips Ill take that more seriously.

Looking at SqD's fault diagnostic it trips instantly, but not like that HARD instant trip of a short circuit, it just clicks off. So either arcing to ground (probably not), shared neutral (possible), grounded neutral (possible) ground fault (not a gfci)

Didn't think to ohm neutral to ground first, could still do that. I know the one circuit had old t12 fluorescents it probably didn't like as well. I'll have a chance to maybe sort this out yet, just don't to run around this house aimlessly without some more ammo. These old houses...could have jboxes buried in the walls or attic I'd never find...

 

[tthh]

Yes, I am convinced I made a AFCI nuisance trip go away by getting rid of a raft of crappy CFL bulbs. Name brand T12 should be better, but maybe.

 

[ramsy]

Yes, I am convinced I made a AFCI nuisance trip go away by getting rid of a raft of crappy CFL bulbs.

That's a new one on me, thanks for sharing

Name brand T12 should be better, but maybe.

Lighting has always caused trouble for GFCI's. Except for 210.8(E) Class-A GFCI protection was never required for lighting, since magnetic T-12 ballasts historically trip 6mA GFCI's.

SQ-D is among the AFCI brands using a similar 30mA Ground Fault function to pass UL1699.

Tripping 30mA AFCI's may depend on the vintage of magnetic ballast, or having more than one such ballast.

AFCI's may also trip with Smart bulbs, and LED's sold on Amazon with a CE mark, not UL listed or FCC tested for Radio interference, known to nuisance trip A/GFCI's.

Clients who insist on controlling lights with their gadgets are known to remove AFCI's, voiding their property insurance subject to construction defect law, since their incompatible Smart bulbs won't be pried from their sockets.

 

[electrofelon]

So what happens when I move the breaker panel 20' away to make way for an addition on this dwelling, fully prepared to install arc faults because I know I need them, and they don't work. First 3 circuits I attempted the afci breakers (SqD) they all tripped. I'm connecting new 12/2 w/g romex to 1970's 12/2 w/g romex so it's not like its knob and tube at least. And even tried an existing circuit that reached the new panel and won't hold the afci.

Probably best to turn down the job and tell the client to find someone else. Also probably suggest they write their state or local government and suggest they adopt an electrical code that is not written by the incompetent NFPA.

 

[User Name]

Probably best to turn down the job and tell the client to find someone else. Also probably suggest they write their state or local government and suggest they adopt an electrical code that is not written by the incompetent NFPA.

Pretty hard to turn down a job that's completed already I could try but I'd kinda like to get paid too.....

 

[electrofelon]

Pretty hard to turn down a job that's completed already I could try but I'd kinda like to get paid too.....

Ok, go ahead and tear EVERYTHING apart trying to find the N-G bond or interconnecting neutrals. Have fun. Il be backpacking, I probably won't have service, sorry......

 

[User Name]

Ok, go ahead and tear EVERYTHING apart trying to find the N-G bond or interconnecting neutrals. Have fun. Il be backpacking, I probably won't have service, sorry......

Thats just me being a smart a** have fun on your trip! Maybe someday I'll get a vacation too...

 

[Ravenvalor]

You can call your inspector and tell him what you are up against. He might give you a pass.

 

[brantmacga]

Looking at SqD's fault diagnostic it trips instantly, but not like that HARD instant trip of a short circuit, it just clicks off. So either arcing to ground (probably not), shared neutral (possible), grounded neutral (possible) ground fault (not a gfci)

When it trips, hold down the test button and then reset (keep holding test button until it trips again). Instant trip is AF, delayed trip is GF.


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