AFCI (hot stuff)

Had a final walkthrough tonite and was presently suprised that many of the items I had found deficient in my report were either taken care of or fixed.
Even the back porch with dangerous guardrails that were attached from the outside with nails in a way if you pushed hard would more than likley cause them to drop three stories.
Ok here is my question.
They at the time were not yet finished with wiring the panel for the bedrooms, however had meanwhile before my return trip installed AFCI as required by the NEC.
When checking I noticed they seemed warmer than the others so I took out my trusty temp gun and found the regular breakers at a room temp of approx 75 degrees but was shocked to find the AFCI breakers hitting 95 degrees.
Is this normal?

AFCIs run warmer than regular breakers.

Mike is twenty degree differential normal.

Typical but I don’t see them often as they are not required in WI.

Try This

Thanks Mike I will call the dedveloper and let him know I was mistaken, though I did tell him I would check.

15 to 20 degrees is not uncommon for AFCI’S…if more than one usually you look at them all and they should all run about the same…to give you a baseline.

Typically the AFCI breaker will be warmer over the standard breakers and also the GFCI breakers will be slightly warmer as well.

i havent see much AFCI in my area yet it might change in 08 depending how much the state will adopt the code with addmendments ]

but the last AFCI i did one trick i did not too long ago i alternated and staggred so keep the hot spot down some.

But i am going to wait and see how it will play out with the new 08 code there are few change along the way.

Merci, Marc

P.S. some early AFCI have some issue with some noise as well but i haven’t confirmed if that is true or what

What year NEC does WI use?

2005 but ammended to remove the AFCI requirements.:slight_smile:

I wrote a propasal asking if NFPA was worried about a panel in unairconditioned space and packed with AFCIs. They blew it off as no substantiation of a problem. I guess we will just have to depend on manufacturers making an afci that will run OK for 30 years at 120f or so.
Personally I bet they find out most of them have failed and are offering no protection after a few summers in Florida and Arizona.
When the central Florida IAEI tested installed GFCIs they found a scary number were not working. That article is probably still in the magazine on

Greg,… I hate to be a pest to you but there is any chance you have a print on this subject because i am little lerry about running the GFCI, AFCI breaker on the outside breaker box and when the sun beating on the box with hot day just like what you describing and i can belive the breaker box can get much hotter than 120° F easly the last time i did check the tempture when the breaker tripped i read it was about 145°F so if you dont mind it…

thank for your time

Merci, Marc


I was part of a study on the AFCI ganged in panels and I never had a problem with them tripping and had as many as 15 side by side in my panel.

The response I have gotten on it from the manufacture is…if you have an elevated AFCI breaker next to another AFCI breaker the heating effect will be the same through the span of the AFCI breakers…not effecting the rise of heat nearly as much as assumed. They also stated the rise is not different than a load being placed on a standard breaker with in an enclosure that may heat up due to increased current draw…

heck I also think the jury is out until a WIDE spread study is done…the study will happen on it’s own once people start to impliment the 2008 NEC and it’s new requirements…

But again I did not see any problems in my panel and never once had an AFCI trip…maybe mine were the recalled ones…thehehehe…no they were Cutler Hammers Versions.