Breakers for C1D2 with switched neut

[s-park-er]

Can I use a 3-pole panel and breakers on a 240V 1ph installation utilizing the third buss to provide grounded conductor interruption? (Specifically Sq-D QO series) or do I have to use the more expensive switched neutral breakers in a 2-pole single phase panel? :roll:

 

[petersonra]

You want to use the three busses as L1, L2 and N?

I don't see why you can't. You can use a 3 phase panel for corner grounded systems. Not much difference.

I am curious though.

 

[rbalex]

You want to use the three busses as L1, L2 and N?

I don't see why you can't. You can use a 3 phase panel for corner grounded systems. Not much difference.

I am curious though.

I'm assuming he's trying to comply with 514.11 since it is the only case where classified locations require opening the neutral; i.e., it isn't a general Art 500-501 requirement. The most commonly used device though is a 3-pole, maintain on/maintain off, push-button switch.

Nevertheless, I agree with you; in absence of a 110.3(B) issue, a 3-pole breaker with the center pole used to open the neutral would work.

 

[s-park-er]

That's exactly what I want to do. I just didn't know if that would be considered as back-feeding the breaker on the neutral leg? I believe QO's can be back fed anyway.