AFCI question

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jsharvey

jsharvey

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Mayetta Ks
Hope this is the right place to ask this question. I was working on a residential trim out today and went to power up the circuits and had an AFCI instantly trip. I tore the circuit apart. removed all the switches and receptacles, ohmed everything out and found nothing. Put it all back together again, turned the breaker on and "POP". I finally tracked it back to an exhaust fan/light that is on that breaker. I know the bathroom isnt specifcally required to be on the AFCI, but since the only way into the bath is through the bedroom it was "suggested" that I put the bath lights on the bedrooms AFCI circuit. Now the question,, Has anyone else ran into this type of situation where a small motor as on the exhaust fan causes the AFCI to trip? or am I looking at a breaker problem? The breaker in question is a Seimens 15A AFCI, and the fan is a Broan model 678 fan/light combo. Thanks in advance.

J.S.Harvey
 
If I recall correctly BPHgravity had posted some info from Siemens saying that they do not recommend suppling small motors with their AFCI breakers.

Small motors....like fans, vacuums etc. why would anyone want to run things like that in a dwelling unit?
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Thanks

Thanks

iwire said:
If I recall correctly BPHgravity had posted some info from Siemens saying that they do not recommend suppling small motors with their AFCI breakers.

Small motors....like fans, vacuums etc. why would anyone want to run things like that in a dwelling unit?
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I looked up the post you refered to. You have a mind like a steel trap remembering a post almost two years old. Guess I'm going to have to start going through some of the older stuff on here. Wish the one who "suggested" I wire things that way would,,,LOL Take care

J.S.Harvey
 
I've never had a fan motor tripa afci, the biggest problem, IME, is contact between the neutral and the groud. Besides, you HAVE to put motors on afci breakers.... How many paddle fans get installed in bedrooms?
 
Afci

Afci

I have had a few interesting problems with afci 2pole cutler hammer Breakers over heating,This led me to call there tech support line. I was told that a gfci and afci breaker opperate the same way with the exception that a gfic trips at 5ma and an afci trips at 30ma. If this is accurate "and I hope it is so I don't look stupid" bath fans are more likely to trip on gfic. If I were you I would double check the nutral didn't get nicked in the cord grip those fans are a tight fit in the J box.
 
1. If this is accurate "and I hope it is so I don't look stupid" bath fans are more likely to trip on gfic.
>>> Yes you are 100% correct, and AFCI will trip on a grounded neutral. Just like a GFCI, but at a higer setting

2. If I were you I would double check the nutral didn't get nicked in the cord grip those fans are a tight fit in the J box.
Yes correct.
The AFCI has to have a load on it to trip if its a neutral to ground contact. Unplug the fan, plug in a 100W pigtail socket in the fan receptacle, Does it trip then?
Can you try another fan?
 
The AFCI has to have a load on it to trip if its a neutral to ground contact. Unplug the fan, plug in a 100W pigtail socket in the fan receptacle, Does it trip then?
Can you try another fan?[/QUOTE]

If there is a fault in the fan to ground. if anything , anywhere on the afci circuit is energized ,and completes the circuit, this connects a path nutral to ground through the fan enough to trip the breaker.
Did you try an ohm meter nutral to ground on the fan??
 
Also, check and see if you have the correct AFCI neutral connected to that breaker. I have had instances that the neutrals were swapped between the AFCI's and they kept tripping.
 
JohnJ0906 said:
I've never had a fan motor tripa afci, the biggest problem, IME, is contact between the neutral and the groud. Besides, you HAVE to put motors on afci breakers.... How many paddle fans get installed in bedrooms?
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Here is bphgravity's post I had been thinking of, Byran is a straight shooter and if he says that Siemens told him this I certainly believe it.

I contacted Siemens some time ago regarding the same issue with AFCI breakers. They gave me three "unofficial" recommendations.


Quote:
1. Do not put 2 afci breakers side-by-side. For best results, don't place an afci breaker next to an other breaker.

2. Do not serve motor loads such as bathroom or attic exhaust fans.

3. Certain cord-and-plug loads such as UPS, vacuum, and a/c units will "false" trip the afci breakers. Avoid these loads whenever possible.
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Hopefully the latest generation of AFCIs do not have this problem.

I agree it makes little sense, I know my Mom would be pretty upset if she could not run a vacuum plugged into a bedroom outlet.

BTW...notice they also make note not to place the AFCIs side by side.....that is also Cutler Hammers thought as well. CH has put a proposal out to eliminate the 42 circuit panel limitation.....we need more room in panels ones the 2008 comes out and requires AFCIs for every 15 and 20 amp dwelling unit circuit.
 
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tom baker said:
1. If this is accurate "and I hope it is so I don't look stupid" bath fans are more likely to trip on gfic.
>>> Yes you are 100% correct, and AFCI will trip on a grounded neutral. Just like a GFCI, but at a higer setting

2. If I were you I would double check the nutral didn't get nicked in the cord grip those fans are a tight fit in the J box.
Yes correct.
The AFCI has to have a load on it to trip if its a neutral to ground contact. Unplug the fan, plug in a 100W pigtail socket in the fan receptacle, Does it trip then?
Can you try another fan?
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Thanks, I'll recheck the wiring today. I had the meter on it yesterday and didn't find anything, but I'll recheck to make sure. I tried three different fan motors in it with the same result, but i didn't try putting a light on inplace of the motor, I'll try that today also. Going to pick up a couple of extra breakers today too and see if I have a bad breaker. If none of these do the trick, it's back to the old drawing board.
 
The one thing you didn`t mention was did you check for a tripping afci with the load being on another part of the circuit ??? Did the light work without the fan being plugged in or were the bathroom light on.Afci`s can be really tricky to troubleshoot.

Personally I go to a receptacle in an affected circuit, make sure all switches on that circuit are off then test from a receptacle to see if there is a neutral to ground fault.This before I tear the entire circuit apart.If there is I sectionalize the circuit till I find the fault.If not then I change the breaker and see what happens.Breakers do come bad from the factory.
 
Wonderfull idea them afci.They never yet done what they claimed and are still not working.What do we do ? lets keep adding them !!!!! Someone is passing a lot of green stamps.Bedrooms were only a test and it failed,so why are we allowing it to go further ? Really makes you rethink who and how much is behind nec.Can $$$$$$ get things put into code that never did what they claimed ? I smell steak dinners.
 
If things go the way they are headed in the code, the AFCIs will be gone in the 2008 code. It will require the use of a type of AFCI that does not even exist, and if it doesn't exist you can't install it.
Don
 
They can definitely cause headaches. On more than one account I have had AFCI Breakers trip due to customers alarm clocks, air purifiers, table lamps, etc. After paying higher prices for AFCI breakers you then have the cost of troubleshooting after the job is over just to find old or faulty equipment is causing the AFCI to trip. But it gets better. You now get to educate the homeowner on why the equipment works on a non AFCI circuit but not on the AFCI circuit.:confused: All this can make you crazy but you tell yourself its just part of the job. So who likes doing commercial work!;)
 
JohnJ0906 said:
I've never had a fan motor tripa afci, the biggest problem, IME, is contact between the neutral and the groud. Besides, you HAVE to put motors on afci breakers.... How many paddle fans get installed in bedrooms?
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Sorry if i'm late to the game, but reading thru this - I sense a requirement to put such things, room fans, exhaust fans..., on afci's. We never put anything other than bedroom plugs on those things and never got a second look from anybody. Is it time to stay quite or do I need to know something here. And, i'm new here, glad to meet ya.
 
JJoyce said:
They can definitely cause headaches. On more than one account I have had AFCI Breakers trip due to customers alarm clocks, air purifiers, table lamps, etc. After paying higher prices for AFCI breakers you then have the cost of troubleshooting after the job is over just to find old or faulty equipment is causing the AFCI to trip. But it gets better. You now get to educate the homeowner on why the equipment works on a non AFCI circuit but not on the AFCI circuit.:confused: All this can make you crazy but you tell yourself its just part of the job. So who likes doing commercial work!;)
Click to expand...

On nuisance trip calls, I just simply tell the homeowner they trip sometimes for no known reason.Which is the truth....I tell them they are required for us to install and we can`t remove them.Some understand but others get irate,oh well ......................
 
Culprits found

Culprits found

Well, I made it back to the house today, spent most of the morning tracking the circuit but finally found the problems. Problem 1, a 2" sheetrock screw through the romex, caught the neutral and the ground wire. Love those sheetrockers. Couldn't get he romex out of the wall so new home run pulled in. Put the circuit back together thought the problem was whipped, turn the power back on. No pop. Turned the fan/light on and "POP"! Went back to tracking the circuit out from the home run box to the only part of the circuit i hadn't previously traced, the can lights. Found ANOTHER neutral/ground short. Traced it through 5 of 6 cans, looked inside the last can and there it was! Someone had "hooked" the lamp socket over the clip inside the can to keep the texture from getting inside the socket! Nice of them to do that, but I bet they have no idea what kind of a headache they caused,,,lol. The one thing that still confuses me is, why did the grounded socket only cause the breaker to trip when i turned on the fan/light?? I would have thought it would have tripped instantly since they work in the same basic fashion as an GFCI.
Thanks for all the help.

J.S.Harvey
 
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If it is a nuetral to ground short, then you need a load on the circuit to trip the afci. I have had the pinched wire in recess can get me before too...
 
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