arc fault and EMT

[Jerramundi]

A juction box is not a outlet. Read the Article 100 definition.

It is if utilization equipment is supplied.

Generally speaking, to discern the NEC definition of an "outlet" from the common vernacular which confuses it with a receptacle, we typically refer to "outlets" as "any point in which the circuit wiring is accessible." Technically speaking, you are correct that per the NEC definition, it requires utilization to meet this definition and a junction box simply used as a pull point would not qualify. However, given the accessibility of the wiring at pull point junction boxes, any junction box could theoretically become an "outlet" in the future. I still refer to all junction boxes as outlets and see no reason to change that.

If wiring protected by metal wiring methods does not have to be protected, then why do I need protection at the outlet the if the circuit never extends beyond such wiring methods? The protection requirement makes some sense if the device is a receptacle, or a light fixture with exposed live parts in the socket when a bulb is removed (or into which someone can screw an old fashioned ungrounded receptacle). It doesn't make any sense if the device at the final box is the end use of the circuit. It seems like they didn't think of this.

Since you obviously want to flex technical speak, I will do the same. It's not that metal wiring methods do not require protection. It's that metal wiring methods between the panel and the first opening do no require protection IF protection is provided at the first opening... I'm just being technical

It does make sense if the device at the final box is the end use of the circuit because you're going to plug in utilization equipment with conductors and the goal is protect those conductors from arcs.

I do agree that this exception (i.e. at the first opening) is a bit odd. It stands to reason that if protection is required on the entire circuit downstream of the first opening, that the entire circuit should be protected.

IMO, it seems like something that was added to aid in the transition to AFCI requirements because if there is an existing MWBC you can separate it at the first opening and AFCI protect one or both circuits. It also aids in the transition because potential compatibility issues with AFCI breakers and panel types. I would wager it will eventually go away as we phase further and further into expanded AFCI requirements.

 

[hbiss]

For a long time these devices weren't even on the market but I have heard they are or will be. I actually wrote a proposal to do away with that section but obviously they knew more than I did. It seems quite ridiculous to me to use 2 devices instead of one. I am not sure why this product is made or where it would be beneficial.

As far as I can see, stand alone AFCI receptacles weren't even "invented" until the 2020 NEC. So I have to assume that if you are on a previous Code and adding receptacles, that's what you have to use. You can't use the new AFCI receptacles legally.

-Hal

 

[Dennis Alwon]

As far as I can see, stand alone AFCI receptacles weren't even "invented" until the 2020 NEC. So I have to assume that if you are on a previous Code and adding receptacles, that's what you have to use. You can't use the new AFCI receptacles legally.

-Hal

I have no idea what you are trying to say. AFCI receptacles have been around for years. The afci that works with the special breakers are new.

 

[jaggedben]

Yes it does.

-Hal

Please review post #2 and tell me what I'm missing.

Maybe I can argue that, if I install the hard-wired LED fixture fed via the aforementionedwiring methods, I don't need an arc fault device to protect "the remaining portion of the branch circuit" because there is no remaining portion.

 

[hbiss]

I have no idea what you are trying to say. AFCI receptacles have been around for years. The afci that works with the special breakers are new.

If they have I've never seen them. I don't have a copy of the 20 Code but when looking at the 17 there is no mention of AFCI receptacles except for the ones that work with the special breakers.

Or am I missing something.

-Hal

 

[Dennis Alwon]

This is from the 2014

(4) Arc-Fault Circuit-Interrupter Protection. Where a
receptacle outlet is supplied by a branch circuit that requires
arc-fault circuit-interrupter protection as specified
elsewhere in this Code, a replacement receptacle at this
outlet shall be one of the following:
(1) A listed outlet branch-circuit type arc-fault circuit interrupter
receptacle

 

[Jerramundi]

I don't need an arc fault device to protect "the remaining portion of the branch circuit" because there is no remaining portion.

Well, on that note, one could argue that 210.12(A)(5) is predicated on the existence of a "remaining portion of the branch circuit" beyond the first opening... and if that doesn't exist, 210.12(A)(5) is not applicable.

Then, you would have to defer to the parent section 210.12 which still requires AFCI protection for that opening... and even the branch circuit supplying it... which seems to suggest that you would have to use an AFCI breaker.

 

[Fred B]

If they have I've never seen them. I don't have a copy of the 20 Code but when looking at the 17 there is no mention of AFCI receptacles except for the ones that work with the special breakers.

Or am I missing something.

-Hal

The 17 doesn't mention the word receptacle at all in 210.12, the reference is to an "outlet branch-circuit AFCI " installed in first outlet of branch circuit. It must be combined with a "listed branch-circuit overcurrent protective device", that to me is a standard circuit breaker or fuse. I have purchased AFCI receptacles that list as meeting AFCI protection when added to conventional breaker at first outlet.

 

[Fred B]

Well, on that note, one could argue that 210.12(A)(5) is predicated on the existence of a "remaining portion of the branch circuit" beyond the first opening... and if that doesn't exist, 210.12(A)(5) is not applicable.

Then, you would have to defer to the parent section 210.12 which still requires AFCI protection for that opening.

Does a plug in cord to an end use device become part of branch circuit when plugged in? If so then even if only one outlet on circuit the extension of a cord and device is covered by "remaining portion of branch circuit".

 

[Jerramundi]

Does a plug in cord to an end use device become part of branch circuit when plugged in?

I would argue yes... so maybe I'm wrong about having to use a breaker in the instance of a single outlet... but the debate (well, one of them anyway, haha) is if AFCI protection is still required at the first opening if its' the only opening... and your point would still say yes to this as it's protecting what's plugged in.

Either (1) 210.12(A)(5) is NOT applicable because there is no remaining portion of the branch circuit and you must defer to the parent section which still requires AFCI protection for the opening and the branch circuit supplying it...

Or (2) 210.12(A)(5) IS applicable because the remaining portion of the branch circuit is that which is plugged in. If that which is plugged in is not an extension the branch circuit, 210.12(A)(5) is no longer applicable.

Either way the answer is the same. AFCI protection is required.

 

[Fred B]

I would argue yes... so maybe I'm wrong about having to use a breaker in the instance of a single outlet... but the debate (well, one of them anyway, haha) is if AFCI protection is still required at the first opening if its' the only opening... and your point would still say yes to this as it's protecting what's plugged in.

But an outlet branch circuit AFCI still would require over current protection. Or you can use a combination AFCI/Overcurrent protection device (AFCI breaker).
I think, but I could be wrong, that all this verbage in the code is a way to continue to use MWBC and AFCI, as most mfg haven't yet gotten a combination AFCI breaker to function with a MWBC without tripping from unbalanced loads.
Also could a switch count as the "first outlet" and if so would you then have to have an AFCI breaker or could you be allowed to install a earlier point that would allow a blank face AFCI protection, I have found those devices as well.

 

[Jerramundi]

But an outlet branch circuit AFCI still would require over current protection. Or you can use a combination AFCI/Overcurrent protection device (AFCI breaker).

I wasn't talking about NOT using an OCPD at all.

I was thinking if it was just one opening on a circuit, and it was concluded that 210.12(A)(5) did NOT apply because there was nothing downstream, in which case you would default to the parent section 210.12, that because 210.12 requires the protection of the branch circuit feeding the opening, that you might have use a AFCI CB instead of just popping in an AFCI receptacle.

But you made a valid argument IMO that what you plug in could be considered part of the branch circuit and so you could make the case that 210.12(A)(5) still applies even for a just one opening on a circuit and thus an AFCI receptacle is acceptable.

Either way, there is AFCI protection required at that one, end-of-run opening.

 

[Jerramundi]

I think, but I could be wrong, that all this verbage in the code is a way to continue to use MWBC and AFCI, as most mfg haven't yet gotten a combination AFCI breaker to function with a MWBC without tripping from unbalanced loads.

I agree that this verbiage about using an AFCI device at the first opening is there to aid in the transition to more AFCI requirements, such as the continued use of MWBC's.

It would allow you to separate the single neutral into two at the first opening and protect one set of conductors, or both with two separate devices. It also solves the issue of incompatibility with AFCI breakers and certain panels - something I've personally run into in which a customer expanded the circuit in the bedroom, thus requiring an upgrade to AFCI protection, but didn't want to upgrade his older panel at the time. So I used an AFCI receptacle at the first opening.

 

[Jerramundi]

Also could a switch count as the "first outlet" and if so would you then have to have an AFCI breaker or could you be allowed to install a earlier point that would allow a blank face AFCI protection, I have found those devices as well.

This is an interesting one that I ran into a couple months ago. My homerun conduit came up from the basement to a switch box in the living room as what I would normally consider "the first opening" and then went to the receptacles... and I was wondering something similar - if I could install an AFCI receptacle at the second j-box in the raceway to protect everything downstream as opposed to having to use a breaker at the panel.

@jaggedben brought up an annoying (haha) albeit interesting point that an "outlet" as defined in 100 is conditional upon utilization. I typically refer to an "outlet" as "any point in which the wires are accessible." If you go with what jaggedben points out, then a switch is not utilization equipment and so you could make the argument that the "first outlet" is actually the second j-box where the first receptacle is... but it seems kinda counterintuitive to the phrasing "first outlet" now doesn't it?

My example is talking about doing it AFTER the literal first box. In your case, I don't see why you couldn't say nipple to a box next to the panel and install a faceless AFCI. I've seen this done before. I've found them as well, but very few supply houses around me actually stock them. They are mostly special order. They stock AFCI receptacles, GFCI receptacles, and faceless GFCI's... but no faceless AFCI's. *womp, womp*

 

[Jerramundi]

Any body else feeling like being an electrician is just prepping them for a future career as a lawyer? haha

 

[jaggedben]

Any body else feeling like being an electrician is just prepping them for a future career as a lawyer? haha

Actually I feel like studying philosophy as an undergrad (which is often prep for law school) prepared me well to be an electrician.

 

[jaggedben]

I'm gonna say that if I were to wire MC cable from a panelboard to a metal box in a ceiling, and wire in an integrated LED fixture, I shouldn't have to provide any arc fault protection. And if inspectors have a problem with that I might consider proposing a revision to the code.

 

[hbiss]

The 17 doesn't mention the word receptacle at all in 210.12, the reference is to an "outlet branch-circuit AFCI " installed in first outlet of branch circuit. It must be combined with a "listed branch-circuit overcurrent protective device", that to me is a standard circuit breaker or fuse.

I see that now. I guess all the nonsense of 1-3 made 4 look like more of the same. And to be honest, I never have nor would I consider using an AFCI receptacle so I never paid much attention to it. They lost me with a concrete encased home run.

-Hal

 

[hbiss]

I'm gonna say that if I were to wire MC cable from a panelboard to a metal box in a ceiling, and wire in an integrated LED fixture, I shouldn't have to provide any arc fault protection. And if inspectors have a problem with that I might consider proposing a revision to the code.

How about joining the crowd that want's 210.12 stricken in it's entirety.

-Hal

 

[Jerramundi]

I'm gonna say that if I were to wire MC cable from a panelboard to a metal box in a ceiling, and wire in an integrated LED fixture, I shouldn't have to provide any arc fault protection. And if inspectors have a problem with that I might consider proposing a revision to the code.

Why would it matter if it were one outlet or 50 outlets? The idea is to protect the conductors from parallel and series arcs. Exposed live parts (i.e. non-integrated) has nothing to do with it. An exposed live part faulting to the box would be a ground fault, not an arc fault. I think you're pushing 210.12(A)(5) a little too far.