Use of 2-pole breakers for 120-volt circuits.

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tonype

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Need help on analyzing this (see Photo) - most breakers are 2-pole. However, most of the users (based on labeling) only require single pole breakers. For instance, a 15-amp 2-pole breaker is labeled "Master Bedroom Attic" on one pole and Master Bedroom Bar (yes, there is a bar in this home - brand new).

Am I missing something in thinking that these should all be single pole breakers?

Regards,
Tony Shupenko

http://i15.photobucket.com/albums/a352/TonyPE/100_1248.jpg
 
Perhaps they are all multwire branch circuits, with the two circuits that share a breaker also sharing the ungrounded conductor?

If this is a new house, and if the bedroom has a bar, howcumzit there is no AFCI for that circuit? :-?
 
Charlie:

From the best of my knowledge, NJ did not enforce the AFCI requirement when it was 1st appeared in the NEC, though it may be now?). This home was started awhile ago so I do not know under which NEC edition is being enforced.

This bar is actually in a room separate from the sleepingn area - this is part of a large master bedroom suite. Would this affect the need for AFCI?

Regards,
Tony
 
If an upset condition occurs in say the "attic" circuit, doesn't this mean that the other circuit wired to the pole (bar) will also trip (even though the 2nd circuit may be okey dokey)? I do not understand how this would be considered a desired set-up. Wouldn't it be much easier to provide 1-pole breakers for these circuits?

Tony
 
My NEC is not handy but yes 210.4(B) I think and Charlie to date a lot of areas amended AFCI....ie Not required. the article quoted was for Oakey. sorry
 
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tonype said:
This bar is actually in a room separate from the sleepingn area - this is part of a large master bedroom suite. Would this affect the need for AFCI?
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I think it would. And I think it is a matter of some controversy as to how it should be handled. It really depends on a number of factors. First there is the AHJ opinion. Well, actually, let's not bother to talk about the other factors. :D
 
tonype said:
If an upset condition occurs in say the "attic" circuit, doesn't this mean that the other circuit wired to the pole (bar) will also trip (even though the 2nd circuit may be okey dokey)? I do not understand how this would be considered a desired set-up. Wouldn't it be much easier to provide 1-pole breakers for these circuits?

Tony
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I'm not positive but I remember seeing a video on this site about this and I believe if your sharing the neutral the intent is that both the hot wires will be off for troubleshooting, so your not working in a box with live wires, even if its not a double pole breaker you're required to add a bar across the 2 that share the neutral, there are also other new things about the nuetral so you don't introduce 220v in case of a broke wire or device
 
The use of two pole breakers here is a design choice _permitted_ by the NEC.

With two pole breakers, a fault on one of the circuits would cause both legs of the breaker to open, and shutting off the breaker shuts off both circuits. IMHO this is a downside of the use.

Some people recommend the use of double pole breakers with multi-wire branch circuits, since this forces the circuits to be on different supply legs, and means that all circuits intentionally sharing a neutral will be off at the same time. This offers a safety benefit, but is really only significant if someone is working on the circuits, in particular if there is 'DIY' work on the electrical system. This is _not_ an NEC requirement unless both circuits feed the same device yoke.

-Jon
 
From the 2008 draft of the NEC.
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210.4(B) Disconnecting Means. Each multiwire branch shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point the branch circuit originates. [ROP 2-10]
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Don

 
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tonype said:
Charlie:

From the best of my knowledge, NJ did not enforce the AFCI requirement when it was 1st appeared in the NEC, though it may be now?).
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AFCI's are "optional" in NJ for the '05 cycle ~ see: http://www.nema.org/stds/fieldreps/codealerts/20051107nj.cfm
Chapter 2 of the electrical subcode, entitled ?Wiring and Protection,? is amended as follows:

i. (No change.) Section 210.12(B) of Article 210, entitled ?Branch Circuits,? is amended to insert the following sentence at the end of the section, ?This requirement shall be considered optional.?
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Tony...are you in NJ ???? ....maybe change your profile..it may help with area specific answers.


tonype said:
This home was started awhile ago so I do not know under which NEC edition is being enforced.

This bar is actually in a room separate from the sleepingn area - this is part of a large master bedroom suite. Would this affect the need for AFCI?
Click to expand...
Not if it's in NJ.

I would check out the hows and ways of the 2P CB...is it a MWBC?
 
As others have stated AFCI protection is optional here. Two pole CB's are permitted for MWBC or two wire circuit. Sounds like a poor design to me to have one circuit breaker trip two circuits if the device isn't one the same yoke.
 
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