I was asked if a 120v. 15a. circuit to a furnace located in a bedroom needs AFCI protection and if I'm not mistaken the answer would be yes. What say you?

George .... I'd love to hear how this application turns out.

As written the furnace would need an AFCI. Nor does the new version allow any exceptions for appliances that use igniters for the gas flame, rather than having a pilot light.

When an igniter operates, that sure looks like a spark to me. Either the AFCI will shut down the appliance .... or I am completely misled as to just what an AFCI is supposed to do!

If you gotta put the smokes on AFCI, I sure don't see any relief for anything else. The only question would be if it was really "in" the bedroom. (the old "closet" question)

Thanks Greg I agree. As for clarification the furnace is a horizontal furnace located above the closet and is serviced standing on a ladder located in the bedroom. I would say it is in the bedroom.

Reno- I don't think the spark ignition would trip the AFCI because it's supplied by a xformer but I could be wrong. The AFCI only sees arc's on the 120v. lines.???

Is this furnace open to the room, or is it in an enclosed area, with just an access panel? If it is in an enclosed area, I would consider it technically not in the "bedroom".
Plus, as a HVAC tech, the last thing I would want to see is the furnace on an arc fault. The risk of the arc fault tripping out is too great, leaving the home without heat when it is needed the most.

George, I agree this should not be tripping the AFCI. The AFCI is really looking for a series of short, high current events. (on the order of 50a or more). I can't see an igniter doing anything like that.

If the AFCI does trip due to the igniter IMO it will be the GFP portion of a AFCI that is causing the trip. (All AFCIs have built GFP protection in the 30 ma range if I recall)

I also with Greg's point about the transformer providing some isolation.

My vote would be that it had to be AFCI protected. I agree that if a smoke alarm has to be protected a furnace should be protected as well.

Tony T.

Iwire, I'm no expert on AFCI design however why do you thing the GFCI side of the AFCI would trip? If it is working properly, the GFCI portions measues power in/power out. If there is a difference of a few millivolts, it trips. If the igniter is grounding out then yes it would trip.

By "above the closet," do you mean above the ceiling of the closet? If so, I would say that it is not in the bedroom. The bedroom stops at the walls, floor, and ceiling.

I just had another inspector call me with a question along the same lines. He asked if a window air conditioner fed with a separate circuit and a single outlet required AFCI protection if it was located in a bedroom. My answer was yes but what if it was a 240 volt cord connected unit? Food for thought.

Tony T.

240v outlets are not addressed in 210.12.
I am not even sure they make a 240v AFCI but I did hear a rumor about a 2 pole for multiwire circuits so I imagine that would work.

George
I didn't think a Furance was allowed in a bedroom via the building code??

I always thought a furnace in the attic was a Jean Sheppard joke but I guess it happens. Around here it is an A/C air handler and not all that unusual. Some AHJs had said they had to make this air conditioned space for a while but that went away with the unified FBC.
The justification was somewhere between "waste energy" and "sweat like a pig"

It's my understanding the intent of the AFCI requirement was to reduce the # of fires starting in bedroom. IE, it's not $$$-justified, but life-justified. So, they didn't require AFCI elsewhere in the house, because smoke alarms would go off with ample time to escape, but in bedrooms, fires in the walls or room are of more immediate danger.

It's up to the AHU for the final call, but were it my decision, I'd take a step back and question "Would an arc-fault in this wire/outlet/etc cause a fire that would let smoke into the bedroom before setting off a smoke detector elsewhere in the house?"

A fire in the closet is just as deadly as if it started on the other side of that unsealed 1.5" hollow-core door. By the letter of the law, one might argue against it, but by the intent of the law, AFCI should be required.

In the 2008 NEC, the AFCI has spread significantly from the 'bedroom' requirement. It's well on its way to being required virtually everywhere in the dwelling.

A Couple of things.
In Ma. They have required smokes in ALL bedrooms for several years, This was to address some of the issues at hand.
Some Mfgrs. do make 2 pole AFCIs' while some have openly expressed that they have no itntentions of making them.Forcing us to a limited choice of equipment.
Fair enough, Free market.

RE: 05, All 120V 15A & 20ckts require AFCI. ANY OUTLET in a bedroom,some removed smokes from this requirement.

I think we're headed for a "quagmire". No one can give or get a straight answer on the intent or bennefits of this.

Unfortunately, I think (and can forsee) A lot of these "safety items",being removed shortly after inspections.In my opinion.. This will create a greater hazard than the one we are trying to prevent.

Skeptic? Yes. Understanding? Yes. Realist? Yes.

Am I alone?

One of the problems I have encountered as an AHJ is a design problem with builders of modular home is that the bedroom arch fault is down streamed to include the hallway lighting and stairwells, down to the basement if a archfault trips how do you find your way down the stairs. I have evan found it downstreamed to the bath fan/light.


Tom

As Tom said having AFCI protecting “too many things”. What happens if or when NEC 2008 we need AFCI everywhere? We have already had three call backs because a vacuum or saw has tripped the AFCI. Will this lead to home owner running a 100’ cord to a non ACFI outlet


TOM L

They will figure out a regular breaker is a whole lot cheaper than a 100' extension cord

Yep , maybe they will get that new book Destroy-It-Yourself Book to help with putting it in


TOM L

This is actually really straight forward, code-wise. The mechanical code (all of them I've ever seen, from all the code making bodies) prohibit gas appliances in bedrooms, bathrooms, and closets/spaces accessed only from bedrooms.
Therefore, your furnace cannot be located anywhere AFCI is required.
If your AHJ approves of the location, then they cannot require AFCI.

Would the attic be considered a space accessed only from the bedroom if the only crawl hole is in the master bedroom closet?

Rereading what I just typed it sure looks like one would conclude yes.

The air handler in the attic is pretty much the norm around here and I can't count how many attics I've had to access from the master closet.

Another thing I've found puzzling about the current arc-fault rules is that your often protecting a circuit that serves a bedroom and not a circuit feeding the other side of the wall. Usually both circuits could just as easily be damaged by the same nail or screw, installed from either side no less. I guess when they have us installing $800 worth of arc fault breakers in every house that won't be an issue any longer.

I would think that the attic, being a separate level of the house, would automatically be considered separate from the bedroom. I'm assuming the "spaces accessed only from bedrooms" language is there to prevent someone from putting a furnace in a closet off the bedroom and trying to argue that it isn't a closet.

IMO, if the air handler is in the attic, there should be an easily-accessible pull-down ladder to the attic at a minimum. Try to make it somewhat easy for the homeowner to change the filter once in a while.

(That reminds me ... I need to change my furnace filter!)