arc faults

[sparky]

I having trouble with three are fault circuits on one new house I have wired, all three breakers trip at random. Never when I am there of course. I have changed all breakers, redone all my connections checking every switch and outlet box light fixture etc. Panel type is Murray(crouse- hinds). Any suggestions what to look for?

 

[bphgravity]

Re: arc faults

Contact the manufacturer. They may be able to provide you with installation recommendations, such as keeping the AFCI breakers separated at the panelboard and limiting the types of loads served.

 

[sparky]

Re: arc faults

I have contacted them and got very little information, I think I knew more then the tech rep i talk to ? I do have breakers stack together .

 

[bphgravity]

Re: arc faults

ITE Siemens sent me a notice that "stacking" the breakers side by side may cause excessive heating due to normal internal breaker operations. They suggested spacing the AFCI's away from each other and if possible away from any other breakers. The document also stated loads like bathroom exhaust fans were being reported as causing nusiance tripping. They continued to suggest not placing these type of loads on the AFCI's if at all possible.

Of course, none of these issues are reported in the listing or instructions?

 

[charlie]

Re: arc faults

ITE Siemens sent me a notice that "stacking" the breakers side by side may cause excessive heating due to normal internal breaker operations.

That leads me to question what do we do when AFCIs are required for every 125 volt, 15 or 20 ampere circuit in a dwelling unit (that is where the AFCI issue is going)?

 

[apauling]

Re: arc faults

i was labeled a nut for questioning the afci bandwagon on another site, this one a little bit. looks like those weren't windmills i was tilting at.

don quixote

 

[hurk27]

Re: arc faults

First you need to elimiate any other possable causes.
Make sure you don't have a AFCI on a shared neutral (Multiiwire circuit)

Turn the breaker off remove the hot and neutral from the AFCI breaker and check for any continuity between the hot or neutral to the ground buss. If there is continuity then it must be located and removed.


I have a open investgation going on right now with UL that involves AFCI's and surge strip's that have L-G MOV's if a motor load is switched off and on like what happens with a click type speed control for a paddle fan, Some AFCI's will trip. So far they havent had very many conplants that involve this type of triping. In every case I removed the surge strip and the problem went away. If there are any others out there who have had this problem check to see if there are surge strip pluged in and if so I'll PM you his E-mail address so maybe we can get more input on this problem.

Here is what he wrote me so far:

By Dave Dini:
Hi Wayne -

Regarding this issue with surge suppressors and AFCIs, I've heard from some other AFCI manufacturers, and they all seem to concur that the surge suppressor/MOV should not be causing AFCI nuisance tripping, but they all are quick to point out that some fan speed controls have caused AFCIs to trip. A new expanded test for fan speed control tripping has been introduced into the AFCI standard. It was also pointed out that if ground current through the MOV was causing tripping, the AFCI was probably tripping on a ground fault as they all have ground fault protection, but if this were the case the problem would also show up on GFCIs, and even with that product they were not aware of any TVSS problems.

That is what I was able to find. If there is any more that you have been able to determine about this from your end, please let me know.

Dave Dini

 

[sparky]

Re: arc faults

If I had ground to neutral contuinity the breaker would trip right away would it not ? I have had other instances where a breaker was tripping and had customer uplug there power strip and problem was solved.

 

[al hildenbrand]

Re: arc faults

Sparky,

Another source, for the neutral to ground current that will get just high enough to take out the AFCI on a ground fault trip (that is, a current between neutral and ground that gets larger than 30 to 50 milliamps), will be electronic fluorescent ballasts, many dimmers and speed controls with indicator LEDs, and other UL approved devices that actually use the Equipment Ground Conductor as a Neutral.

If your client has enough of these devices contributing leakage current, that may be the cause.

 

[hurk27]

Re: arc faults

By Sparky: If I had ground to neutral continuity the breaker would trip right away would it not ?

Not with AFCI's that use a 30-50ma GFP in them. It will only trip after a load is applied. Not like a GFCI which has a 5ma trip level which will trip instantly. Also the resistance of the wire will come into play in this also as if the ground path is through two EGCs back to the panel where two EGCs gets tied together where two circuit run meet in the same box then the AFCI will trip with very little load but when only one circuit and EGC is involved then it might take more of a load on the circuit to trip the AFCI breaker.

 

[sparky]

Re: arc faults

Correct, but in my situation the breaker holds for some times several weeks before tripping. I would be able to identify the problem if I could make it trip while I was there.

 

[al hildenbrand]

Re: arc faults

Sparky wrote: Any suggestions what to look for?

What is the anecdotal evidence from the dwelling occupants?

So far, you haven't offered any info from them. . .The key info I would listen for is what was happening, or not happening, when the power went off. Time of day, who was home, what people were doing, stuff like that.

The client, most often, tries to troubleshoot based on what they understand, but the really useful information, at least to me, is found in the story of life in the house as the power stops, not about the power itself.

From your description of the work you've done, and, simply, the time lag between outages, I strongly suspect a load caused problem. Who is there when the power stops. Talk directly, and patiently, with that person(s) about the most recent event. Given how hard you've tried to solve this, they should be paying attention as well, and I bet they have knowledge they don't know they have.