arc fault protection

[wyboy]

Does a 120 volt circuit supplying a low voltage transformer in the attic (The transformer feeds a 12 volt light fixture in the living room.) require arc fault protection? Circuits supplying devices in the attic do not require arc fault protection and only 120 volt circuits require arc fault protection in the required areas? Any thoughts?

 

[WorkSafe]

I think the code is pretty clear on this:

(A) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed indwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.

If the outlet is installed IN the attic, it is not required by code to be AFCI.

My opinion.

 

[tom baker]

However, its likely this outlet is not a dedicated circuit and is fed from an AFCI circuit breaker.
Unless you are under the 2005 NEC, which only requires AFCIs for the bedroom outlets.

 

[wyboy]

I think the code is pretty clear on this:

(A) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed indwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.

If the outlet is installed IN the attic, it is not required by code to be AFCI.

My opinion.

The outlet

 

[wyboy]

The outlet, according to what I can get from the definition of outlet in 100, is in the living room. The 120 volt circuit feeds the transformer which changes voltage but is transformer utilization equipment? If so then you are correct. My concern is a transformer does not ?use? electricity at least as defined by the term utilization equipment.

 

[wyboy]

The outlet

The outlet, according to what I can get from the definition of outlet in 100, is in the living room. The 120 volt circuit feeds the transformer which changes voltage but is transformer utilization equipment? If so then you are correct. My concern is a transformer does not ?use? electricity at least as defined by the term utilization equipment.

 

[kwired]

The outlet, according to what I can get from the definition of outlet in 100, is in the living room. The 120 volt circuit feeds the transformer which changes voltage but is transformer utilization equipment? If so then you are correct. My concern is a transformer does not ?use? electricity at least as defined by the term utilization equipment.

You have good point there, and this could be a little tricky. Most of the time the branch circuit will have other outlets that are not as questionable and therefore AFCI protection will usually be necessary anyway. Does this circuit only have outlets that would not require AFCI protection?

 

[wyboy]

You have good point there, and this could be a little tricky. Most of the time the branch circuit will have other outlets that are not as questionable and therefore AFCI protection will usually be necessary anyway. Does this circuit only have outlets that would not require AFCI protection?

It is a custom house with lots of LV lights and there is nothing but LV lights on that circuit. All the lights are in the living room with the transformers in the attic above.

 

[kwired]

It is a custom house with lots of LV lights and there is nothing but LV lights on that circuit. All the lights are in the living room with the transformers in the attic above.

Then I would have to say it all depends on where the "120 volt outlet" is located.

The lighting outlet that is in the living room is not a 120 volt outlet and the AFCI rules would not apply.

The lighting transformer may or may not be seen as an outlet, but it is not in the space requiring AFCI protection.

I would have to say in most lighting systems the system must be listed as a system and where the power supply connects to the premises wiring is likely to be considered the outlet.

There was recent similar discussion in a thread regarding recessed luminaires - the "outlet" location was questioned as the connection box is usually not in the room that the luminaire is serving. I think most of us came to the conclusion that the can is a listed unit and that the outlet is the point where premises wiring connects to the listed unit - which is not in the room, yet in most cases there will be other outlets on same circuit requiring AFCI protection so AFCI will be installed anyway.

 

[wyboy]

Then I would have to say it all depends on where the "120 volt outlet" is located.

The lighting outlet that is in the living room is not a 120 volt outlet and the AFCI rules would not apply.

The lighting transformer may or may not be seen as an outlet, but it is not in the space requiring AFCI protection.

I would have to say in most lighting systems the system must be listed as a system and where the power supply connects to the premises wiring is likely to be considered the outlet.

There was recent similar discussion in a thread regarding recessed luminaires - the "outlet" location was questioned as the connection box is usually not in the room that the luminaire is serving. I think most of us came to the conclusion that the can is a listed unit and that the outlet is the point where premises wiring connects to the listed unit - which is not in the room, yet in most cases there will be other outlets on same circuit requiring AFCI protection so AFCI will be installed anyway.

Thanks!!!!!

 

[kwired]

Thanks!!!!!

That is just my opinion, you may want to run this by your AHJ if this is a job that will be inspected.