New 2-Pole Combo Type Arc Fault Breaker

[Little Bill]

First off Mr. Moderator(s): I don't know if this is the correct forum for this question. If it is not. please move it to the correct one.

Have any of you used this new 2-pole combo type arc fault breaker from Siemens? You are suppose to be able to share a neutral with these. I have heard/read so much about false tripping with the regular combo types when a neutral is accidentally contacting a ground wire or people trying to share neutrals. This would be a great product if it works, lower costs on wiring. I just wanted to know if any of you have experience with these. I'm including a link to this breaker on Siemen's web site.
Thanks,
Little-Bill

http://www.sea.siemens.com/us/News/Construction/Pages/2-pole-CAFCI.aspx

 

[Little Bill]

Maybe It's Not New

Maybe It's Not New

Perhaps I shouldn't have called it new since I re-read the web page and saw that it was in 2009. But it is new to me. Has no one tried these, or have I ask a redundant or stupid question?:-?

 

[Chamuit]

I have used the GE 2-pole AFCI breaker, just this year. The only thing I don't like is, if there is a fault, both poles trip (as it should) and you lose power in a broader area.

 

[Dennis Alwon]

Dp combo arc faults have been around however I would avoid using them unless it is an existing install that requires it. The idea of both circuits tripping is very annoying and I would never deliberately make a new install with these in mind. Ge has it's own newer version which is basically 2 sp afci that are put together with handle ties-- you cannot do this with other brands- only GE.

 

[Little Bill]

Thanks for both of your replies. I guess I was just looking at the less wire run and wasn't thinking about both circuits opening. I knew you couldn't share neutrals on a AFCI and was excited when I saw this new toy.

 

[Dennis Alwon]

Thanks for both of your replies. I guess I was just looking at the less wire run and wasn't thinking about both circuits opening. I knew you couldn't share neutrals on a AFCI and was excited when I saw this new toy.

If you can get your supplier to stock 14/2/2 that would help. It is a 4 wire nm cable with a black & white wire and , I believe a red with a white wire with a red stripe.

 

[gndrod]

Perhaps I shouldn't have called it new since I re-read the web page and saw that it was in 2009. But it is new to me. Has no one tried these, or have I ask a redundant or stupid question?:-?

Hi Little Bill,

Siemens demonstrated this dual AFCI at the 2009 NECA in Seattle last year. The positive about this device is the LED indicates which leg has the fault event. This cuts the trouble shooting time in half to locate the fault origin. Unfortunately the two branch circuits are off-line and cannot be reset until the one fault is isolated.

This is a major reason for not using the dp type setup for two branch circuits in critical areas or in high-end residential wiring where the nuisance is not a good thing. The GC may have to answer to the client for saving wire in dwelling shared BC runs that may not be a wash with extra down time costs. From past experience, it is best to include a note in the contract mentioning that extra quality taken for client comfort is more important than saving $$ using MWBC wiring in touchy AFCI circuits as a contractors choice.

 

[kwired]

... I have heard/read so much about false tripping with the regular combo types when a neutral is accidentally contacting a ground wire or people trying to share neutrals...

The so called 'false tripping' will still happen if current is flowing outside the MWBC. The only convenience added with the two pole unit is the ability to run a MWBC. You still have to avoid unintended current paths through equipment grounding conductors or neutrals that are not part of the MWBC or even current from another hot conductor from another circuit entering the AFCI circuit.