# Multiple AFCI tripping randomly



## kharasym (Jul 3, 2011)

OK I have a service call tomorrow for a house I wired and finished 2 years ago. Everything was tested and worked perfectly fine until recently. She tells us that all her AFCI's trip at the same time and at random times also. Another of our guys was out there a few months ago to try fix it. He load tested with no problems. Checked all the breakers and the test on them works fine. He tried moving breakers to different locations to avoid having multiple AFCI's adjacent to each other. He was unable to get the problem to repeat when he was there. Now we are going back and absolutely baffled as to what could be the cause of this. The homeowner recently said that the problem seems to occur during heavy rainfalls. I cant see how a sump pump can cause this when it has a dedicated circuit that is not AFCI. All the AFCI's are run with separate 14/2 feeds. 


Anyone ever experienced anything like this before? 
I am located in Canada BTW. Not that that should affect this problem.


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## backstay (Feb 3, 2011)

kharasym said:


> OK I have a service call tomorrow for a house I wired and finished 2 years ago. Everything was tested and worked perfectly fine until recently. She tells us that all her AFCI's trip at the same time and at random times also. Another of our guys was out there a few months ago to try fix it. He load tested with no problems. Checked all the breakers and the test on them works fine. He tried moving breakers to different locations to avoid having multiple AFCI's adjacent to each other. He was unable to get the problem to repeat when he was there. Now we are going back and absolutely baffled as to what could be the cause of this. The homeowner recently said that the problem seems to occur during heavy rainfalls. I cant see how a sump pump can cause this when it has a dedicated circuit that is not AFCI. All the AFCI's are run with separate 14/2 feeds.
> 
> Anyone ever experienced anything like this before?
> I am located in Canada BTW. Not that that should affect this problem.


I had a treadmill on a dedicated circuit tripping other arcfault breakers. This was a CH panel. The fix was Cutler Hammer coming out with the new breaker with the diagnostic lights on it.


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## Semi-Ret Electrician (Nov 10, 2011)

A CH engineer mentioned AFCI's trip if near some radio, TV or microwave towers, depending on what frequency they operate.

Variable frequency drives might be a problem as they ramp up and down through these harmonics.


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## kharasym (Jul 3, 2011)

I didn't mention that this was an Eaton BR panel. I do have a sub panel in that house and can't remember if the AFCI's are in the main or the sub. The main panel is located in the exercise room with the sump across the room. The sub is basically directly above the sump but on the other side of the wall in her mechanical room. The mechanical room does have a boiler, fan coil and several grunfos pumps near by. 

We have never had any kind of problem like this before, a lot of our panels are near mechanical equipment too. 

I will certainly look into the treadmill and mechanical stuff as sources of the problem tho. Thanks for the info.


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## joshuamccann (Sep 19, 2013)

Since you said it happens during heavy rainfall, could water/moisture getting inside the panel and causing the breakers to trip? That's a just a wild guess.


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## papaotis (Jun 8, 2013)

joshuamccann said:


> Since you said it happens during heavy rainfall, could water/moisture getting inside the panel and causing the breakers to trip? That's a just a wild guess.


not so wild. i worked a panel on a remodel that someone else installed the serviceand while working in the panel on a rainy day, water started dripping down the back of the panel. im like wtf, found out later the service installer made his own connections to to the poco and water was running down THROUGH the wire!:no:


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## kharasym (Jul 3, 2011)

Can't think of how water could get in the panel. We run acwu out the back of the meter and through the bottom plate into the top of our panels. I guess if flashing wasn't done correctly above the meter it could find its way down.

Another great thing I will look into. Thanks.


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## papaotis (Jun 8, 2013)

actually, the job i was talking about, the hook up at the mast was so poorly done that rain was able to migrate all the way down to the panel. once water finds a way in it follows gravity!


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## kharasym (Jul 3, 2011)

I see. Bleh I hate overhead services.


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## Bugz11B (May 12, 2013)

Could be a issue with the utility power, lightning, or humidity in the panel. last time I saw multiple afci's trip at same time was a service problem on the entire street (random times usually afternoons), you mentioned rain so i would say humidity (if panel is outside or in a humid area) chances are if it were water or lightning it would trip more then the afci's but not totally impossible.


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## FallenEdict (Sep 22, 2013)

If it's the humidity in the mechanical room, try throwing on a afci receptacle on each circuit. (wouldn't normally recommend those).


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## electricmalone (Feb 21, 2013)

We had an issue with CH BR AFCI breakers for months straight. They finally sent out special "shielded" breakers. The neutral pigtail to neutral bar was wrapped in a foil like wrapper with heat shrink over it. Something about radiation/microwaves/disturbance in the air... Whatever it was worked.


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## macmikeman (Jan 23, 2007)

electricmalone said:


> We had an issue with CH BR AFCI breakers for months straight. They finally sent out special "shielded" breakers. The neutral pigtail to neutral bar was wrapped in a foil like wrapper with heat shrink over it. Something about radiation/microwaves/disturbance in the air... Whatever it was worked.


You beat me to it. Every time the fleet pulls int Pearl Harbor the afci's everywhere go haywire.


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## Semi-Ret Electrician (Nov 10, 2011)

macmikeman said:


> You beat me to it. Every time the fleet pulls int Pearl Harbor the afci's everywhere go haywire.


Firecontrol radar can kill a seagul in a second...and trip an AFCI:laughing:


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## Meadow (Jan 14, 2011)

Something could be getting wet in a wall if it happens after heavy rains. 


A sub pump could do that if the load is seen as a heavy arcing signature or has severe interference but not likely. Still test the pump though.


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## macmikeman (Jan 23, 2007)

Who puts afci's on sump pumps? And Why?


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