AFCI tripping

J

JoeNorm

Senior Member
Location
WA
New construction. AFCI started tripping a lighting circuit. Carpenters are in doing finish work so it's possible something happened.

But I am wondering if the first thing to try is just replace the breaker? Since it is easy. Before I go tearing the hole place apart looking for something.

It's a HomeLine 15amp AFCI breaker. Has anyone seen these fail? I have had pretty good luck with them so far.
 
Snicker... here we're talking about my own fun with AFCI and the enjoyment they can bring. It's possible your carpenters missed a stud and have pierced a wire. In my case after a FedPac > QO panel swap, one of my breakers would trip every time a kitchen light was turned on... tracked it to a bedroom receptacle where the ground had fallen off the screw. At any rate, good luck finding the offender.
 
Is it only tripping when finish carpenters are there and use certain equipment?

I have one finish carpenter friend that has a miter saw with automatic control to start a shop vac that is hooked to the saw as a dust collector. The saw works fine on AFCI circuits and so does the vacuum but I think whatever the vacuum controller uses must be a solid state controller that doesn't play well with AFCI. Works fine on receptacle that has GFCI only protection.
 
For occasional middle of the night random type AFCI trips that I can't reproduce standing there, I temporarily replacing the breaker with a class B GFCI (or GFPE), for homeline that would be a HOM115EPD or Siemens QE115 . I Leave it in for twice whatever the AFCI trip interval was. So if they said it tripped once a week I leave it in for two weeks.
If that puppy trips (30mA) I know I have serious problem to track down, if it does not trip I'm back to hunting ghosts.
 
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JoeNorm said:
AFCI started tripping a lighting circuit.
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Narrow the possibilities

What type of fault does diagnostic indicate?

Does flipping switches off isolate trouble?

Did you Isolate & Megger for shorts - resistive faults trip AFCI
 
ModbusMan said:
Snicker... here we're talking about my own fun with AFCI and the enjoyment they can bring. It's possible your carpenters missed a stud and have pierced a wire. In my case after a FedPac > QO panel swap, one of my breakers would trip every time a kitchen light was turned on... tracked it to a bedroom receptacle where the ground had fallen off the screw. At any rate, good luck finding the offender.
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Had one the helper installing a light that pinch the wire when it was hung. fixed it and no more tripping, but it was a chase around to find what had happened.
JoeNorm said:
New construction. AFCI started tripping a lighting circuit. Carpenters are in doing finish work so it's possible something happened.

But I am wondering if the first thing to try is just replace the breaker? Since it is easy. Before I go tearing the hole place apart looking for something.

It's a HomeLine 15amp AFCI breaker. Has anyone seen these fail? I have had pretty good luck with them so far.
Click to expand...
Most times I've come across that, have ultimately found loose connections, or at times was a pinched wire from a staple or connector, Had also where the carpenter was using 2 1/2 inch rock screws and just nicked the wire, Why that long he just said "he had them".
 
tortuga said:
For occasional middle of the night random type AFCI trips that I can't reproduce standing there, I temporarily replacing the breaker with a class B GFCI (or GFPE), for homeline that would be a HOM115EPD or Siemens QE115 . I Leave it in for twice whatever the AFCI trip interval was. So if they said it tripped once a week I leave it in for two weeks.
If that puppy trips (30mA) I know I have serious problem to track down, if it does not trip I'm back to hunting ghosts.
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Are those breakers readily available for you?

Googled both looks like the Homeline is around $200 give or take a little, the Siemens maybe about half that in most cases. I remember wanting a QO120EPD one time nearly 20 years ago for deicing cable - supply house did not stock them and price was way more than the heating cable accessory GFP devices were and they also had those so went with that instead.
 
kwired said:
Are those breakers readily available for you?

Googled both looks like the Homeline is around $200 give or take a little, the Siemens maybe about half that in most cases. I remember wanting a QO120EPD one time nearly 20 years ago for deicing cable - supply house did not stock them and price was way more than the heating cable accessory GFP devices were and they also had those so went with that instead.
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Yeah a while back I ordered a sleeve of the 15's and 20's and the price about the same as a AFCI.

Here is a seller selling them on ebay for $59 & free shipping:
https://www.ebay.com/itm/233344460232
 
This crew has already sent a screw into my wire once(previously) so it's definitely possible there is a real issue.

I was more just wondering if people have seen these particular breakers be faulty enough to not trust them.
 
JoeNorm said:
I was more just wondering if people have seen these particular breakers be faulty enough to not trust them.
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Recent IEEE publications are reporting an epidemic of past & present equipment failure to trip, other studies show xFCI failing in the energized state. Have not yet heard about failures to hold during load.
 
ramsy said:
Recent IEEE publications are reporting an epidemic of past & present equipment failure to trip, other studies show xFCI failing in the energized state. Have not yet heard about failures to hold during load.
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Though construction finished almost ten years ago now, that could explain why one of our AHJ's demanded a GFCI outlet for a drinking fountain, rather than a GFCI breaker?
 
Most likely is the equipment the finish carpenters are using. I've had them use a miter saw and it tripped the AFCI everytime it was attempted to be used. Switched it to the garage GFCI receptacle and no problems there.
 
jim dungar said:
Have there really been multiple vetted reports, or just the single one you reference in a different post?
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You responded to two IEEE studies introduced by forum member brycenesbitt

The older circuit breaker failures

Federal Pacific Electric (FPE) .... fuses?

The owner of the pictured property got a notice of non-renewal from their insurance company (this is California) and forced onto the State's "Fair Plan". The company cited the Federal Pacific Electric (FPE) panels. 1961 construction date. Fair enough, those FPE breakers are junk...
forums.mikeholt.com

The newer circuit breaker failures

Leviton

Wondering how many companies that use Leviton load centers and breakers have tons of nuisance trip calls?
forums.mikeholt.com

You also responded to my link citing GFCI failure rates

QO Plug-on Neutral CAFCI/GFCI Circuit Breakers

Unless the arcs that are being artificially generated by this test setup are not representative of real world loose connection arcs, I believe there is some scientific substantiation that AFCI's can operate as designed. With that said, I'm not at all convinced that they are great; they probably...
forums.mikeholt.com

brycenesbitt may have shared more study links I haven't read.
 
Little Bill said:
Most likely is the equipment the finish carpenters are using. I've had them use a miter saw and it tripped the AFCI everytime it was attempted to be used. Switched it to the garage GFCI receptacle and no problems there.
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It trips within a second of being turned on. It is a lighting circuit with no receptacles on it.

Interestingly, it does not trip immediately, like a short would(you know the feeling). It lets the lights come on for a split second, then trips
 
jim dungar said:
These are IEEE papers not studies.

Then what multiple IEEE papers are you saying exist? It looks like most of what you reference are papers from insurance and inspection companies.
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Without good cause to discredit the IEEE papers, insurance may wield it to reject the equipment.
 
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