Home>Discussions>ELECTRICAL & LIGHTING>Type of breaker for bath vent
7 posts / 0 new
Last post
dcalabro
Type of breaker for bath vent

I'm installing a new for bathroom light, vent, and ceiling fan + light for an adjoining bedroom. I was planning on putting the circuit on a a combination arc fault 15amp breaker since part of the lighting relates to a bedroom but would this cause any problems for the bath vent since it's a motor? I've read that motors can sometimes cause issues with arc fault or gfci breakers but im not sure how accurate it is.

Fencepost
Re: Type of breaker for bath vent

To clarify, the AFCI is only required on bedroom OUTLETS. If the circuit is only supplying overhead lighting, it's not necessary.

Re: Type of breaker for bath vent

Actually, the 2011 Code defines "Outlet. A point on the wiring system at which current is taken to supply utilization equipment".

All lights, switches, receptacles & smoke detectors in most rooms must now be on Arc-Fault breakers. Further, if one mounts a light or fan over a shower or tub it most likely will require additional GFCI protection, even if feed from an Arc-Fault Breaker, which provides some small amount of ground fault protection.

Very few appliances will trip a combination arc-fault breaker. We tried everything under the sun to do so in a class I taught.

Also, why run #14 (15A) when #12 (20A) cost just a few cents more and the AFCI breaker cost the same and you can put more outlets on it?

dcalabro
Re: Type of breaker for bath vent

The way I have it laid out is that I was trying to assign 1 breaker for each bedroom with only 3 or 4 outlets each. then put lighting on a lighter circuit.

Breaker 1 20A AFCI - BedroomA 3 outlets
Breaker 2 15A AFCI - BedroomA 1 ceilingfan/light + Bathroom main light and vent, and vanity light
Breaker 3 15A AFCI - BedroomB ceiling fan+light and closet light, BedroomC ceiling fan+light and closet light
Breaker 4 20A AFCI - BedroomB 5 outlets
Breaker 5 20A GFCI - dedicated bathroom outlet

Note: the 3 outlets on BedroomC are not listed because they are already on an existing circuit I will not be removing.

My thoughts being that if each room has typical tv and air conditioner window unit that in itself will draw a considerable load. Since that works out to very small loads on breaker 2 and 3, I figured I could use the extra 14/2 and 14/3 I have. I'm just not sure if Breaker 2 is allowed to be AFCI or if i have to give the bathroom lighting its own GFCI breaker.

Fencepost
Re: Type of breaker for bath vent

I have yet to see a combination AFCI/GFCI device... why not?

(And I'll defer to Semi-Retired, he's much more in tune to the codes than I am.)

The NEC's terminology often doesn't jibe with common usage. For example:

NEC term: what everyone else calls it
----------------------------------------------
Outlet: Pretty much any distribution point or endpoint of electricity, such as a receptacle (outlet), lamp (light fixture), fan, appliance, etc.
Luminaire: Lamp (light fixture)
Lamp: Light bulb (NOT a light fixture!)
Receptacle: Outlet (plug-in; where you plug something in)

No wonder people find it confusing.

canuk
Re: Type of breaker for bath vent
dcalabro wrote:

I'm installing a new for bathroom light, vent, and ceiling fan + light for an adjoining bedroom. I was planning on putting the circuit on a a combination arc fault 15amp breaker since part of the lighting relates to a bedroom but would this cause any problems for the bath vent since it's a motor? I've read that motors can sometimes cause issues with arc fault or gfci breakers but im not sure how accurate it is.

Shouldn't be an issue with a bath exhaust fan -- they're generally brushless motors so no arching --- besides you are having bedroom ceiling fans on AFI breakers.

dcalabro wrote:

The way I have it laid out is that I was trying to assign 1 breaker for each bedroom with only 3 or 4 outlets each. then put lighting on a lighter circuit.

Breaker 1 20A AFCI - BedroomA 3 outlets
Breaker 2 15A AFCI - BedroomA 1 ceilingfan/light + Bathroom main light and vent, and vanity light
Breaker 3 15A AFCI - BedroomB ceiling fan+light and closet light, BedroomC ceiling fan+light and closet light
Breaker 4 20A AFCI - BedroomB 5 outlets
Breaker 5 20A GFCI - dedicated bathroom outlet

Note: the 3 outlets on BedroomC are not listed because they are already on an existing circuit I will not be removing.

My thoughts being that if each room has typical tv and air conditioner window unit that in itself will draw a considerable load. Since that works out to very small loads on breaker 2 and 3, I figured I could use the extra 14/2 and 14/3 I have. I'm just not sure if Breaker 2 is allowed to be AFCI or if i have to give the bathroom lighting its own GFCI breaker.

If it were me I would simplify the wiring for the bathroom. A regular 20 amp breaker feeding the bathroom light , fan and have a GFCI receptacle --- simpler and cheaper.
Also, don't feed the light from the GFCI receptacle load side -- this way when the GFCI trips you will still have light .

The fan and lights in a bathroom don't have to be GFI protected unless they are directly in a wet area like a shower.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.