# OK, This One Has Me Stumped



## Seven-Delta-FortyOne (Mar 5, 2011)

I don't usually ask for advice here, but maybe I'm just overlooking an obvious solution, and someone has run into this before.

New construction, just installed lights. 1 circuit has 3 5-watt LED can lights, and 1 chandelier, containing 6 60-watt incandescent bulbs.

Any combination of 2 lights works fine, but as soon as all three are on, the 15 amp AFCI breaker trips. 

I put an amp meter on each light individually, and on the breaker with every combination of 2 lights turned on, and never got more the 3.1 amps, which is exactly as it would calc out to be.

I'm going back over prolly next week, and start pulling stuff apart, but if anyone has any clues, I'd be glad to hear them.

Oh, and the fixtures are all HO supplied units from HD. 

Thanks.


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## 480sparky (Feb 1, 2009)

It's most likely an AFCI issue, not an overload issue.


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## Seven-Delta-FortyOne (Mar 5, 2011)

That's what I was leaning towards. 

I switched the load to different afci breaker, and it did the same thing, so now I just have to trace down the issue.

The strange part is why each unit is fine, but the issue only shows up when all three switches are on at the same time. I wonder what it is about all three being on at the same time that would cause some type of arc-fault.


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## TxElectrician (May 21, 2008)

Any location have a neutral from another circuit present?


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## Tinstaafl (Jan 6, 2008)

Are there any dimmers involved?


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## 480sparky (Feb 1, 2009)

TxElectrician said:


> Any location have a neutral from another circuit present?


That would trigger the AFCi regardless of how many lights are turned on.


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## Seven-Delta-FortyOne (Mar 5, 2011)

TxElectrician said:


> Any location have a neutral from another circuit present?





Tinstaafl said:


> Are there any dimmers involved?


No to both of these.


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## 480sparky (Feb 1, 2009)

Remove all the lamps (LED and incandescents) from all the lights and see if the AFCI trips.

If not, then the issue is with the lamps. If so, it's in the wiring.


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## woodchuck2 (Feb 27, 2008)

What are you using for switches? Basic toggles will create an arc sometimes, enough to trip an AFCI breaker.


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## MTN REMODEL LLC (Sep 3, 2010)

If it appears to be a function of all lights on....ie max current.... could it be a bad neutral splice??????

Just a WAG


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## wireless (Nov 2, 2006)

Or each light has minor arcing but all three lights is enough to trip afci


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## Seven-Delta-FortyOne (Mar 5, 2011)

480sparky said:


> Remove all the lamps (LED and incandescents) from all the lights and see if the AFCI trips.
> 
> If not, then the issue is with the lamps. If so, it's in the wiring.


What if there was an arc fault in the neutral?


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## Seven-Delta-FortyOne (Mar 5, 2011)

woodchuck2 said:


> What are you using for switches? Basic toggles will create an arc sometimes, enough to trip an AFCI breaker.


Yes, that's what's in there. 

But still, why only when all three switches are activated?


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## 480sparky (Feb 1, 2009)

Seven-Delta-FortyOne said:


> What if there was an arc fault in the neutral?


No current will be able to flow with no load impressed on the circuit.


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## MTN REMODEL LLC (Sep 3, 2010)

I really do not understand how arc faults work.... so this is sole conjecture and possibly rediculous thinking..... (I'm a DA GC)

But as this seems to be a higher current related issue,....

what if you pop a recep adapter in each light succesively as you move downstream, and plug in a heater (any high draw convenient appliance)...

and if it trips the arc fault, might that indicate/isolate an arc fault between the tripped location and upstream.....????


(For further questioning, if you had some impaired insulation (stripped off or nail intrusion in some romex) would the likelyhood of an arc fault be more likely (sensative) to current , or just voltage, or both????)

Just curious

Best


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## woodchuck2 (Feb 27, 2008)

Seven-Delta-FortyOne said:


> Yes, that's what's in there.
> 
> But still, why only when all three switches are activated?


I would go through the diag like 480 mentioned but be mindful of the switch possibly being a problem. Try with and without the lights per switch to see if it is the lights, the wiring or the switch. Move the lights around or try a different load on each circuit to verify the problem. Have you checked the connection at the breaker itself? May be it takes a larger load to create enough resistance to trip the breaker. Is there stress on the wire at the breaker causing some stress to the breaker?


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## Seven-Delta-FortyOne (Mar 5, 2011)

woodchuck2 said:


> I would go through the diag like 480 mentioned but be mindful of the switch possibly being a problem. Try with and without the lights per switch to see if it is the lights, the wiring or the switch. Move the lights around or try a different load on each circuit to verify the problem. Have you checked the connection at the breaker itself? May be it takes a larger load to create enough resistance to trip the breaker. Is there stress on the wire at the breaker causing some stress to the breaker?


Thank you. Yes, I checked the connections at the breaker, and condition of wiring in general. All appears to be fine.

When I go back over there, I'll just start troubleshooting like for any issue, it's just that this one makes no sense to me. 

The switch thing is interesting. Do you often have problems with snap switches on afci circuits? Do you have a favorite switch to use in those situations?


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## Seven-Delta-FortyOne (Mar 5, 2011)

480sparky said:


> No current will be able to flow with no load impressed on the circuit.


That was my point. If the arc-fault is in the neutral, then without load on the circuit, it would never show up. :thumbsup:


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## Fault Current (Jan 22, 2014)

Are they 120 V LED lamps or are they LV LED from a power supply? The switching power supply to the LED's could be a problem.

I would disconnect the LED's from the circuit first, nothing should happen when only the incandescents are connected unless there is a problem with wiring. 

The AFCI detects high frequency signals on the circuit that would be produced if a low level arcing fault were present. False tripping can occur from signals generated by arcing motor brushes, low quality power supplies, or dimmers. Newer AFCI's are supposed to be more sophisticated and more resistant to false tripping.


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## pappagor (Jan 29, 2008)

so did you get it fixed or did you call a real gek


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## MTN REMODEL LLC (Sep 3, 2010)

Bump.... Common Seven Delt.... We're curious.:thumbsup:


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## Seven-Delta-FortyOne (Mar 5, 2011)

Havn't been back over there yet.

Waiting to make a trip out of it. I have a tub to install once tile goes in.

I'm sure it's an afci problem from the home despot fixtures the ho purchased. 

I'll let you all know what I find out. :thumbsup:


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## MarkJames (Nov 25, 2012)

Random find, but maybe it will help:

http://www.bcd.oregon.gov/boards/electelv/board_pack/2011/20110526/JohnPowell.pdf


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## pappagor (Jan 29, 2008)

i would bet it is the light sockets unscrew all the bulbs the turn on power and leve it on and then screw in the bulbs one at a time if it dose not pop then it leads to think that the switch need to be look at more


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## Red Adobe (Jul 26, 2008)

Sorry so late on this one

I recently found a similar issue with some can lights, 2 rows of them each on their own 3 way DECRA switches.
The problem was a loose quick stab in a switch, took awhile to get the switches cycled right but it tripped the breaker.

So my advice is start with the switches , If I think its a sw then I tie the wire together and if problem persits I know its something else


edit.

If there is any #12 mixed in with the #14 this can make for some issues as well


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## Cletis (Mar 2, 2014)

Disconnect each load one at a time then reset afci til you find culprit. I'm betting power supply or dimmer, then bulbs, then maybe wiring and such but I doubt it


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