210.4(C) Exception No. 2

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ibew441dc

Senior Member
2008 NEC
210.4 Multiwire Branch Circuits.
(C) Line-to-Neutral Loads. Multiwire branch circuits shall supply only line-to-neutral loads.

Exception No. 1: A multiwire branch circuit that supplies only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device.
Proposal- Delete Exception No. 2

Substantiation-210.4(B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.
 

Smart $

Esteemed Member
All those who oppose ? nay

All those who approve ? eye


So far the eyes have it;)
Nay...

The exception refers to the opening of the overcurrent device, not the disconnecting means... slight difference in some instances, vast in others. What of fuse-protected mwbc's? They cannot be used for simultaneous L-L load whereas a two or three pole circuit-breaker-protected mwbc can.
 

raider1

Senior Member
Staff member
I second the nay.

Exception #2 requires the branch circuit overcurrent device to open all ungrounded conductors simultaneously, whereas the disconnect requirement allows the use of listed handle ties which under most circumstances would not open all breakers under an overcurrent condition.

Chris
 

ibew441dc

Senior Member
Smart $ said:
Nay...

The exception refers to the opening of the overcurrent device, not the disconnecting means... slight difference in some instances, vast in others. What of fuse-protected mwbc's? They cannot be used for simultaneous L-L load whereas a two or three pole circuit-breaker-protected mwbc can.
raider 1 said:
I second the nay.
Exception #2 requires the branch circuit overcurrent device to open all ungrounded conductors simultaneously, whereas the disconnect requirement allows the use of listed handle ties which under most circumstances would not open all breakers under an overcurrent condition.

Chris
210.4(B) is a new requirement in the 2008 NEC. Its very requirement now makes 210.4(C) Exception 2's a mute point.........!!

;);) Wait a minute after further review, I stand corrected and agree 100% with you guys's accurate observation.

Thanks!:cool:

The Nays Have it 3 to 1......the OP didn't stand a chance:grin:
 

ryan_618

Senior Member
Dan: I made this proposal in the 2008 comment stage and ws rejected by the panel, for the same reasons stated above, which are accurate.
 
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