AFCI heat

[romex jockey]

We in Vermont, due to state addendum to the NEC, generally stuff panels with AFCI's more than what the rest of the (NEC compliant) world is doing.

We've done so since the 99' cycle.

One strange problem is the heat AFCI breakers seem to assume, this is without any substaintial load applied.....

So standard practice has been to seperate AFCI's with normal breakers.

Just wondering if any others have come to this conclusion.

 

[tom baker]

Re: AFCI heat

I have heard that before. I recently submitted to Mike Holt a AFCI update for his newsletter. My draft included to space AFCI's, the draft was reviewed by Cutler Hammer AFCI folks, they said spacing is not necessary, the afci does not generate heat, the load does.

 

[don_resqcapt19]

Re: AFCI heat

Tom,
How can it not generate some heat? It is an electronic device with an internal power supply and there is no way that it doesn't generate some heat. If they have managed to make a power supply that is 100% efficient, which is the only way that it wouldn't make any heat, there would be many markets far more lucrative then making AFCI beakers. I really doubt that they have succeeded in doing this. Of course, as with all breakers some additional heat will be produced by the I?R losses within the breaker, but even with no load the AFCI will produce some heat. While I don't think that the heat produced by the electronics within the AFCI is any type of problem, I wonder why the AFCI manufacturers continue to provide misleading information. It really makes me wonder what they are trying to hide from us.
Don

 

[romex jockey]

Re: AFCI heat

I know what i feel in a panel, as well as what i probe out for the breakers draw Tom.

With minimal load these breakers assume a notable temperature, even my customers have noted this and inquired when i've made the mistake of stacking them.

As it has been 4 yrs , the better inspectors here will tell you to space out the AFCI's

The latest edition of the IAEI is not as yet on line (march/april 03)

Note pg 18 and the "Truth about AFCI's" ,in which two manufacture's reps finally fess up about AFCI specifics long debated and inquired about.

They are obviously backpeddaling here, having caught rumour of possibile legal confrontation they are now publicizing what was not clear prior to 210.12, more to thier own protection than our information.

Now if there are those here that live in the real world, and NOT the phoney baloney one the reps would have us subscribe to, i have a real and valid field problem here.

AFCI's heat up

Field installers please answer up, Rep's need not apply

[ March 30, 2003, 08:15 AM: Message edited by: romex jockey ]

 

[templdl]

Re: AFCI heat

You know the drill, If something that is warm when it is expected to be cool to the touch it often times is referred to as being hot. All this stuff is relative.
AFCI breakers do get warm because of their electronic circuitry. Standard breakers is also are allowed to get warm as they are loaded up to their rated ampacity. Breakers do have heating watt ratings which are often considered when the size an A/C unit is selected for an electrical distribution or control room.
Of course this is by no means important to know in a home environment but heating is nevertheless acceptable and comes with the territory.
If the heating of the AFCI doesn't compromise the temperature rating of the cable or cause the AFCI itself or other breakers within the enclosure to derate, then what's the big deal??

 

[tom baker]

Re: AFCI heat

Interesting comments on AFCI's and heat. I'll forward to the CH person who commented on the newsletter I wrote for Mike Holt and see what he says.