AFCI :how to wire

[Cjmcelectric]

Hello gents,

I was wondering about afci receptacles wiring to a existing multi -wire branch circuit . Can they be wired into a shared neutral ?
Thanks,
Chris Mc

 

[augie47]

Is there an AFCI receptacle on the market ?
Having not seen one I would assume they are (or will be) like a GFCI receptacle. They can be connected to a multi-wire (shared neutral) branch circuit as long as the neutral sharing is on the line side of the device.

 

[Dennis Alwon]

Leviton has a afci that is available now

 

[infinity]

Can these be used with NM cable?

 

[augie47]

Thanks.
Found them after you advised me.
Proud of them, are they not $$$$

 

[augie47]

Can these be used with NM cable?

Rob,
I would say they could be when used as "replacement" receptacles in AFCI areas as noted in 406.4(D)(4) {'11 Code}, but as 210.12 required installations they could not be used with NM.... (as of now )

 

[Dennis Alwon]

I was told that there is an effort in 2014 to allow nm cable to the first receptacle if an afci receptacle is installed. Who knows if that will happen.

I think the afci receptacles are $30-$40

 

[Cjmcelectric]

I thought they would have same wiring and operate as gfi but with short circuit protection on the Branch circuit. I was also wondering do the measure arc fault in milli amp like ground fault protection?

 

[don_resqcapt19]

I was told that there is an effort in 2014 to allow nm cable to the first receptacle if an afci receptacle is installed. Who knows if that will happen.

I think the afci receptacles are $30-$40

From the 2014 NEC Draft. (subject to change at the ROC and annual meeting stages)

(A) Dwelling Units.

All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected as described by (1), (2), (3), or (4).

(1) A listed combination type arc-fault circuit interrupter, installed to provide protection of the entire branch circuit.​

(2) A listed outlet branch circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit where all of the following conditions are met:
a. The branch circuit over current protection device shall be a listed circuit breaker having an instantaneous trip not exceeding 300 amperes.
b. The branch circuit wiring shall be continuous from the branch circuit overcurrent device to the outlet branch circuit arc-fault circuit interrupter.​

c. The maximum length of the branch circuit wiring from the branch circuit overcurrent device to the first outlet shall not exceed 15.2 m (50 ft) for a 14 AWG or 21.3 m (70 ft) for a 12 AWG conductor.
d. The first outlet box in the branch circuit shall be identified.

(3) A listed outlet branch circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit where the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet is installed using RMC, IMC, EMT, Type MC, or steel
armored Type AC cables meeting the requirements of 250.118 and using metal outlet and junction boxes.

(4) A listed outlet branch circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit where the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet is installed using a listed metal or nonmetallic conduit or tubing encased in not less than 50 mm (2 in.) of concrete.

Exception No. 1: If RMC, IMC, EMT, Type MC, or steel armored Type AC cables meeting the requirements of 250.118, metal wireways, metal auxiliary gutters, and metal outlet and junction boxes are installed for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, it shall be permitted to install an outlet branch-circuit type AFCI at the first outlet to provide protection for the remaining portion of the branch circuit.

Exception No. 2: Where a listed metal or nonmetallic conduit or tubing or Type MC Cable is encased in not less than 50 mm (2 in.) of concrete for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, it shall be permitted to install an outlet branch-circuit type AFCI at the first outlet to provide protection for the remaining portion of the branch circuit.

Exception No. 3: Where an individual branch circuit to a fire alarm system installed in accordance with 760.41(B) or 760.121(B) is installed in RMC, IMC, EMT, or steel sheathed cable, Type AC or Type MC, meeting the requirements of 250.118, with metal outlet and junction boxes, metal wireways or metal auxiliary gutters, AFCI protection shall be permitted to be omitted.

[Informational Note No. 1: For information on types of arc-fault circuit interrupters, see UL 1699-2011, Standard for Arc-Fault Circuit Interrupters.

Informational Note No. 2: See 29.6.3(5) of NFPA 72-2010, National Fire Alarm and Signaling Code, for information related to secondary power supply requirements for smoke alarms installed in dwelling units.

Informational Note No. 3: See 760.41(B) and 760.121(B) for power-supply requirements for fire alarm systems.​

​

 

[Speshulk]

I was told that there is an effort in 2014 to allow nm cable to the first receptacle if an afci receptacle is installed. Who knows if that will happen.

I think the afci receptacles are $30-$40

So basically at this point the receptacle is the same price as the breaker, which makes the installation of a circuit with a receptacle more expensive than using an AFI breaker if you can't use NM.

 

[Cavie]

I'm guessing they will be allowed for extending existing circuits. OH! Wait I forgot! That's common sence. My bad.

 

[kwired]

I thought they would have same wiring and operate as gfi but with short circuit protection on the Branch circuit. I was also wondering do the measure arc fault in milli amp like ground fault protection?

I can't give you any specifics on the AFCI receptacles, but they are not a replacement for overcurrent protection, and they are not replacements for GFCI's either. They could have some features of a GFCI or even a circuit breaker, but arc fault protection in my understanding is their primary function and those other functions are not provided by the device to an extent to replace other devices.

The AFCI circuit breaker is a circuit breaker and an arc fault circuit interrupter all in one assembly.

 

[Dennis Alwon]

The draft will not allow NM but I was told that would change-- I won't believe it until I see it but the person I got the info from is pretty reliable and is very involved in code issues. Of course he could be incorrect.

 

[don_resqcapt19]

The draft will not allow NM but I was told that would change-- I won't believe it until I see it but the person I got the info from is pretty reliable and is very involved in code issues. Of course he could be incorrect.

I don't see how. I did not find any comment that CMP 2 could act on to permit NM as the supply to an AFCI device. It is my understanding that the CMP cannot introduce anything new at the ROC stage.

 

[peter d]

Leviton has a afci that is available now

I see it listed on their site but is it available anywhere yet?

 

[Dennis Alwon]

I don't see how. I did not find any comment that CMP 2 could act on to permit NM as the supply to an AFCI device. It is my understanding that the CMP cannot introduce anything new at the ROC stage.

Well that is good to know- I will ask him further about this issue.

 

[Dennis Alwon]

I see it listed on their site but is it available anywhere yet?

I saw it on platt electric website http://www.platt.com/search.aspx?q=leviton+AFCI+receptacle

 

[al hildenbrand]

I see it listed on their site but is it available anywhere yet?

I've had them in stock on my truck since the end of November. My local Graybar has been stocking them since then.

 

[Dennis Alwon]

I don't see how. I did not find any comment that CMP 2 could act on to permit NM as the supply to an AFCI device. It is my understanding that the CMP cannot introduce anything new at the ROC stage.

I am wondering now if he was talking about a NC amendment.... Again I will check

 

[al hildenbrand]

I was wondering about afci receptacles wiring to a existing multi -wire branch circuit . Can they be wired into a shared neutral ?

This is the key to your question. Most of the answers,above, are not for an existing branch circuit, but, rather for a new installation. An AFCI receptacle, on an existing multi-wire branch circuit, can't have its load terminals connected to protect the downstream conductors that include the shared neutral (this is similar to the limitation of a GFCI receptacle in the same situation).

I was also wondering do the measure arc fault in milli amp like ground fault protection?

At present, the Leviton AFCI receptacle is the only such device that I am aware of, and I have not been able to find any technical information about it. I can assume that the device discriminates between good and bad arcing with a signal processor that does a number of complex manipulations of the voltage and current waveforms. Whether any one of those manipulations is down in the milliamp current amount is not published yet.