AFCI

J

Jimmy7

Senior Member
Location
Boston, MA
Occupation
Electrician
Do I need an Afci breaker here? I was hired by a customer to replace three existing ceiling fixtures with recessed lights that are all switched together. The house was built in the 50’s and the lights are located in the first floor ceiling, so there is no attic above. Between two of the fixtures I had to replace a damaged cable, and the run of cable was probably exactly 6’. I figured I would just install an afci breaker in the Square D QO panel and be done. Unfortunately, the panel was full of tandem breakers, and the circuit I needed was on one and was also part of multi-wire branch circuit. The circuit was the black of a three wire at the panel. What do you do in cases like this? Is there a way to afci a MWBC?
 
Jimmy7 said:
Is there a way to afci a MWBC?
Click to expand...
If you must do so there is 2 pole AFCI's, which would be what you must use with Square D panels. There are some others that no longer have a GFP component in their AFCI's and because of that will work using two single pole units but would still require a handle tie since it is a MWBC.
 
Jimmy7 said:
replace three existing ceiling fixtures with recessed lights that are all switched together. The house was built in the 50’s and the lights are located in the first floor ceiling, so there is no attic above. Between two of the fixtures I had to replace a damaged cable, and the run of cable was probably exactly 6’.
Click to expand...
210.12(E) Branch Circuit Wiring Extensions, Modifications, or Replacements.
If branch-circuit wiring for any of the areas specified in 210.12(B), (C), or (D) is modified, replaced, or extended, the branch circuit shall be protected by one of the following:
..............

Exception:
AFCI protection shall not be required where the extension of the existing branch-circuit conductors is not more than 1.8 m (6 ft) and does not include any additional outlets or devices, other than splicing devices. This measurement shall not include the conductors inside an enclosure, cabinet, or junction box.

Argument could be made that you both Modified and Replaced and exception would not apply as it was not an extension thus what you did would need to be AFCI.
 
Fred B said:
210.12(E) Branch Circuit Wiring Extensions, Modifications, or Replacements.
If branch-circuit wiring for any of the areas specified in 210.12(B), (C), or (D) is modified, replaced, or extended, the branch circuit shall be protected by one of the following:
..............

Exception:
AFCI protection shall not be required where the extension of the existing branch-circuit conductors is not more than 1.8 m (6 ft) and does not include any additional outlets or devices, other than splicing devices. This measurement shall not include the conductors inside an enclosure, cabinet, or junction box.

Argument could be made that you both Modified and Replaced and exception would not apply as it was not an extension thus what you did would need to be AFCI.
Click to expand...
The new/replaced section of cable certainly would certainly kick in 210.12(E).

A replacement receptacle would require AFCI protection per 406(D)(4) but that could be an AFCI type receptacle and doesn't necessarily need to be protection of the entire branch circuit.

I don't see any similar rule for replacing switches nor do I see any similar rule for replacement of a luminaire. Some may look at converting a luminaire attached to a flush outlet box being converted to a self contained type like recessed lighting to be a different case but NEC doesn't specifically address that situation either from what I can tell.
 
hbiss said:
Well, let's see. Add this to your job cost:

https://www.supplyhouse.com/Square-D-HOM220CAFI-Homeline-2-Pole-Circuit-Breaker-and-Combination-Arc-Fault-Circuit-Interrupter-120-240V-20A?utm_source=bingad&utm_medium=Shopping_Electrical&utm_campaign=Shopping_X_Electrical_X_SSC_Class D/E/DI/NS/New&utm_campaignid=590264932&utm_adgroupid=1228155559489347&utm_targetid=pla-4580359300952749&utm_product_id=HOM220CAFI&utm_matchtype=e&utm_keyword=default&utm_adtype=&utm_adgroup=Electrical Catch-All_X_X_X&utm_searchquery=square d 2 pole afci breaker&utm_category=Electrical&msclkid=b4c37cea0405159c22b21b435e374013

Then I would have to charge another 50% if I had to have something like this permitted and inspected.

-Hal
Click to expand...
Fine for a 2 pole application but big issue is SD doesn't have a tandem AFCI and OP situation would require that, or consider the optional method of an AFCI receptacle.
 
hbiss said:
Well, let's see. Add this to your job cost:

https://www.supplyhouse.com/Square-D-HOM220CAFI-Homeline-2-Pole-Circuit-Breaker-and-Combination-Arc-Fault-Circuit-Interrupter-120-240V-20A?utm_source=bingad&utm_medium=Shopping_Electrical&utm_campaign=Shopping_X_Electrical_X_SSC_Class D/E/DI/NS/New&utm_campaignid=590264932&utm_adgroupid=1228155559489347&utm_targetid=pla-4580359300952749&utm_product_id=HOM220CAFI&utm_matchtype=e&utm_keyword=default&utm_adtype=&utm_adgroup=Electrical Catch-All_X_X_X&utm_searchquery=square d 2 pole afci breaker&utm_category=Electrical&msclkid=b4c37cea0405159c22b21b435e374013

Then I would have to charge another 50% if I had to have something like this permitted and inspected.

-Hal
Click to expand...
Could still be lesser cost method on some existing installs if you are being forced to add AFCI protection than running new cables.

May or may not be more cost on new installs, just depends on the details. Two single pole units is going to be around 25% that cost, so the rest comes down to cost difference in wiring methods used and any labor differences though many typical situations likely would still best off using two single pole AFCI's and separate cables for the branch circuits.
 
You must log in or register to reply here.
Top