Ok, so I rewired the entire house for a new 200 amp service (old was only 50), and everything is working great. Except, last night I went to switch off one of the new AFCI breakers for the bedroom so I could wire up a new light and the breaker was quite warm. The only load on the thing was a couple of alarm clocks and one light! Actually both AFCI breakers were warm. All standard breakers were cool to the touch. Question = is this normal? Seems like the things are supposed add to the safety of the system and heat is not a particularly good thing when it comes to electrical system. Feedback appreciated so I can either rest easy or pull the sucker (inspection already finaled…).
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The AFCI was warm. How warm? Glowing and smoking would be very bad. In this case do not take time to turn off your computer. Do not pass GO. Do not collect $200. Call in the fire department and get the family out.
Too hot to comfortably keep your finger on would likely be a problem. Just warm enough to detect wouldn't. These units are fairly self contained and an internal fault would just cause it not to work. The higher heat, short of smoking, situation could be a pitted bus bar so it would warrant investigation but an internal failure would probably be contained and only need the AFCI replaced.
To stay safe be vigilant on testing the breaker. If it fails replace the breaker. Otherwise if the breaker was not too hot to comfortably touch, a judgment call, I would leave it in place.
If your comfortable doing it you might turn off the main, double check to make sure the buss bars are dead, lift the breaker and using a mechanics mirror and a strong light inspect the stab where the breaker makes contact. I don't think you will find anything but I might do it just to be thourough.
If it makes any difference, as if there weren't some incompitent pros and quite a few workmanlike duffers, I'm an electrician.
4Lorn1,
Any info/experience you want to post on AFCIs as we gain experience with them - please do so.
_______________________
10 .... I have laid the foundation like an expert builder. Now others are building on it. But whoever is building on this foundation must be very careful.
11 For no one can lay any other foundation than the one we already have--Jesus Christ.
1 Corinthians 3:10-11
Ok, so I'm reporting back. I went to Seimans web site and under FAQ section it states that due to internal electronics AFCI's are warm to the touch. Five "attah-boys" for the poster who commented on the voltage conversion issue. YES, I can now sleep well at night! Seimans claims AFCI's operate at about 100 degrees (based on a 73 degree ambient testing). Good news for me, as this "felt" about right. Why don't they publish this information with their product? It seems like this is information that the end-user should be made aware of.
Great! Thanks for the followup!_______________________
10 .... I have laid the foundation like an expert builder. Now others are building on it. But whoever is building on this foundation must be very careful.
11 For no one can lay any other foundation than the one we already have--Jesus Christ.
1 Corinthians 3:10-11
Hi Buildboy, I am an engineer for a leading breaker manufacturer. AFCI breakers do operate at a higher temperature than "standard" breakers. However, all circuit breakers / loadcenters must meet certain temperature rise standards as defined by U.L. The circuit breaker manufacturer is not required to advise the installer / end user that a certain type of breaker has a "warmer" operating temperature. Glad to hear you are using AFCI breakers for your installation. Kay
Kay, that the manufacturer is "Not required" to disclose/advise the user that the product will have a 25* rise in temperature seems like a poor reason for not mentioning it.
If I noticed a hot breaker I would "assume" I had a problem, as did Buildboy. Any electrical item that is hot to the touch is a warning flag.
Joe H
Certainly, if they retail-package them for sale in places like HD and the other big box stores, there should be a notice on them that these things run warm. It'll save returns from some DIY'ers, and ultimately save the manufacturer money.
One would think the pros would know this, but AFCI's are so new that a note inside bulk packaging wouldn't be a bad idea, either.
JoeH, Thanks for your comments. Panelboards/Loadcenters are designed to limit the temperature rise on any current carrying part to a maximum of 65 degrees C above an ambient of 40 degrees C maximum.
There are numerous electrical products that are "hot to the touch" that are operating well within there design criteria. Kay
Kay, true nuff, BUT, if I was checking a load center and ONE breaker was hot to the touch.........
Maybe in 5 years when these things have been around and it's common knowledge it would be a different story.
Case in point, called AOL to bitch about my DSL. Instant service, repairman from Pac Bell was here the SAME DAY at 7PM. (When did you ever get the phone company the same day you called?)
Turns out the DSL box itself is bad, not AOL, not the phone line.
Clue number one? Box is hot to the touch..........
If the AOL service center guy had asked me that while he was on the phone,that I could have saved them the trouble of calling the phone company & the price of a service call.
If it's hot & it ain't a toaster, I'm suspicious.
Joe H
JoeH, Please define " hot to the touch". Thanks. Kay
all circuit breakers / loadcenters must meet certain temperature rise standards as defined by U.L.
Can you tell what us those standards are for residential laodcenters?_______________________
Worship is not an hour in a building; even in a building dedicated to God.
Worship is an encounter with the holy presence of God!
Bob:
Seimans website said "...UL Standard 489 Section 7.1.4.1.3 which states - Temperature rises on handles, knobs, and other surfaces subject to user contact during normal operation shall not exceed 60°C (140°F) on nonmetallic surfaces. "
There you have it!
You might check out link below for added AFCI info.
sea.siemens.com/reselec/product/rzafcifaq.html#14
I got the impression Kay was talking about some o0ther standards aw well_______________________
Worship is not an hour in a building; even in a building dedicated to God.
Worship is an encounter with the holy presence of God!
Hi Bob, UL 67 . Thanks. Sandy
Thanks for the reply. The buses should be fine. It's a brand new panel with copper buses (and mounted indoors). ACFI's (both of them) were warm. Not hot. I'd equate it to touching the glass of a 14V flashlight after it's been on for about 1/2 hour (like my Makita flashlight when I've been in the crawl space under the house for too long). Breakers test fine. When I installed them they pushed firmly onto the stabs, so contact should be good. And, as mentioned in my post, all "normal" breakers were not detectebly warm. Have a feeling this is normal based on other posters comment regarding voltage conversion. Think I might call Seimans and see if I can find anyone there to confirm this is normal. If it is, the damn instructions should contain a note regarding such. Thanks again. I'll report back if I find anything enlightening from the manufacturer since these babies are a new product. Thanks again.
This isn't surprising. Ulike the standard breaker, the AFCI's have a bunch of electronics in them. For example, see one design at http://www.zlan.com/afci_c4.htm . See the block in the upper left labelled "AC/DC conv"? It's a power supply that generates 5V DC for the rest of the circuitry. Generates a little bit of heat, as well (a few tenths of a watt).