210.12 Arc-Fault Circuit-Interrupter Protection
Arc-fault circuit-interrupter protection shall be provided as required in 210.12(A) (B), and (C). The arc-fault circuit inter- rupter shall be installed in a readily accessible location.
(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 by any of the means described in 210.12(A) (1) through (6):
(1) A listed combination-type arc-fault circuit interrupter, installed to provide protection of the entire branch circuit
(2) A listed branch/feeder-type AFCI installed at the origin of the branch-circuit in combination with a listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet box on the branch circuit. The first outlet box in the branch circuit shall be marked to indicate that it is the first outlet of the circuit.
(3) A listed supplemental arc protection circuit breaker installed at the origin of the branch circuit in combination with a listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet box on the branch circuit where all of the following conditions are met:
a. The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch- circuit arc-fault circuit interrupter.
b. 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 conductor or 21.3 m (70 ft) for a 12 AWG conductor.
c. The first outlet box in the branch circuit shall be marked to indicate that it is the first outlet of the circuit.

Video explaining an AFCI

http://youtu.be/OWJQqWjlQyo

Siemens has a fairly good overall description of AFCIs

http://w3.usa.siemens.com/us/SiteCo...AFCI-Technical-Overview-Presentation.pdf

I am still not sure I understand all I know about 210.12(A)(3)

Why a arc fault breaker and a device type on the same circuit?
What is a "supplemental arc protection circuit breaker"?
Leviton talks about their device but the breaker is just alluded to.
http://www.bobselectricco.com/bob-s...itarc-faultcircuitinterrupterreceptacle.

A tag line from bobselectricco.com link above, seems like another 'new' item is mandatory with the '14 changes.

"AFCI receptacles must be UL listed for compatibility with specific magnetic circuit breakers that are commonly found on the market today or used downstream from a new type of breaker called an SAP (Supplemental Arc Protection) breaker."

Reading thru the entire text, some text alludes that the AF device works with 'standard mainstream breakers'; yet the above quote is deeper within the text??

I just wonder why you would want the inline device if you are replacing the breaker anyway.
I doubt there is going to be a Zinsco SAP breaker anytime soon.

Greg:
Existing old "FPE" 150 amp panel. EC adding three (3) new 2 wire circuits. He installs a 60 amp, 2 pole FPE CB, 1" EMT raceway (3'6"), 5' +/- conductor length. into a 100 amp MLO new sub panel. Three compliant AFCI CBs in new sub panel. Normal TR devices.

IMHO, that is compliant, and the AFCI receptacles are not required. Agree??

Agree, that is the most elegant solution. Just about any modern panel will work for the sub. They make AFCIs for just about anything still in production.

I am still not sure what a SAP is and why you would use one.

Now, I can think of a few definitions for 'SAP'.

Seriously, I have to find time to read the '14 Changes!

From the cite Joe posted
"listed Supplemental Arc Protection circuit breaker"

I believe you and I still do not know what it exactly is??

I am starting to think it is another "product" that only exists in the code. The breaker manufacturers don't seem to be pitching them on the web sites yet.

Here's a checklist by Square D
Joe Tedesco, NEC Consultant

Join Date: Mar 2012
Location: Maine
Posts: 10 Default

Received this from Leviton Engineering:--------------------------------------------------------------------------------

A listed outlet branch circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit in combination with a listed branch circuit overcurrent protective device where all of the following conditions are met: The branch circuit wiring shall be continuous from the branch circuit overcurrent device to the outlet branch circuit arc-fault circuit interrupter.
• 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.
• The first outlet box in the branch circuit shall be marked to indicate it is the first outlet of the circuit.
• The combination of the branch circuit overcurrent device and outlet branch circuit AFCI is identified as meeting the requirements for a "System Combination" type AFCI and is listed as such.


In a nutshell this means that we list the OBC AFCI Receptacle/standard breaker combination with UL. A listing will then be available that says you use Leviton’s OBC AFC receptacle to meet code requirements when using the following breakers: xxxxx, xxxxx, xxxxxxx

Trick is…right now UL has yet to issue a standard that contains testing requirements to meet this code so therefore we cannot submit for a listing. As soon as the new standard is developed we’ll proceed with the listing.



Emanuel Ramondino
Applications Engineer

T: 631-812-6705
F: 800-832-9538
eramondino@leviton.com

Leviton Manufacturing Co., Inc.
201 North Service Road
Melville, NY 11747
www.leviton.com


So, the good news is that we are not waiting on the overcurrent device manufacturers to decide to play ball...If UL would just get going on this........

on the other hand:
--------------------------------------------------------------------------------

http://www.joetedesco.org/JoeTedesco/Presentation1.pdf


Square D seems to have other ideas

after alot of extensive reading, it seems the whole contraversy comes down to available fault current(300a vs 500a)..The accepted fault current available for single family dwellings has widely and historically been accepted at 300A.
Now we have another study, sponsered by overdurrent device manufacturers, that claim the actual fault current available is 500A. This is the number the overcurrent manufactuers are using to sway Code making panel into demanding a listed system combination AFCI.

It seems that The UL rep did not buy that argument in the code making panel stating that once the 300a fault current is reproven for single family dwellings (worse case scenario), the rest of the data in the manufactuer's report would be faulty and the established magnetic trip ability of standard overcurrent devices with an additional ABS AFCI would be more than adequate to mitigate any arc fault problems likely to be encountered.

UL’s representative on the Code Panel voted affirmation on this action with the following comment:
“While we support the panel action, continued support is dependent upon review of additional
data that would confirm the availability of sufficient short circuit current capability at the panel of a
typical installation.
“The arc fault protection of the branch circuit will be provided by a system that includes an outlet
branch circuit AFCI, a circuit breaker having a known instantaneous trip current and a branch
circuit of a limited length and resistance to ensure that the fault current is sufficient to trip the
breaker during a parallel arcing fault at the installation point of the outlet branch circuit AFCI. The
latest UL Research Report4 takes into consideration the impact of the available current at the
panel on the acceptable length of the branch circuit home run to the first outlet. Calculation shows
that as the available current at the origin of the branch circuit varies, so does the allowable length
of the home run.
“Additional study is needed to provide data regarding the current available at the origin of the
branch circuit in a typical installation. From this data, the panel will be able to determine if
modification of the panel action should be considered at the ROC.”

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