AFCI breakers warm?

[tcrosby]

Please help.....New construction AFCI breakers finding them warm to touch. Temp. tested at 100 degrees. Is this normal?
Called several electricans and got mixed bag of answers....
Help?

[Marc D. Shunk]

Yes, that's completely normal. The manufacturers say that they may have up to a 40 degree temperature rise over ambient. Sorta throws you for a loop, doesn't it?

For this reason, some installers prefer to leave a blank space or a regular breaker between groups of AFCI breakers. Keeps them from heating each other up so much. Give a little room in between to cool off. This isn't expressly required by any manufacturer, but some installers consider it good practice.

[Jeffrey R. Pope]

Originally Posted by Marc D. Shunk

Yes, that's completely normal.

Agreed. . .

[William J. Decker]

Yep. They actually have computer circuitry in them that run a little hotter than normal. The circuitry looks at the wave form and checks it against the wave form of an arc.

Normal.

[Michael W. Gault]

I would note if they are stacked more than three together as I remember at least one AFCB manufacturer recommended this be the max...

No real concerted agreement on this either though...

[David A. Andersen]

Even the GFCI runs into the 90's with nothing on the circuit.

Low voltage transformers are another one (up to 120).

[RAY THOROMAN]

I understood it most AFCI's are rated 140 degrees F. As do not all breakers need to have the temp ratings on them?

Anything around or over this temp. I state futher evaluation by a licensed electrician.



Ray

[pdickerson]

So how much power does that represent? Maybe 10 watts each AFCI (a total SWAG)? Times maybe 10-15 breakers per panel after the new code edition. Times several hunderd thousand new panels per year... Do you suppose these costs were considered by the code generators at NFPA?

[Paul W. Abernathy]

lol....well I spoke with Eaton on this and they have done tests....stacking does not harm anything as they have a good allowance of heat factored in.

IN regards to spacing....the new 2008 NEC will make that moot..since all 125V 15 & 20A circuits will require AFCI so people higher than US have determined it is not a problem......

[Greg Fretwell]

There are over 32 pages of comments on AFCIs in the ROC. NFPA is still pressing ahead on the universal requirement.