Thanks to everyone for posting your replies to this discussion!
My rant on this particular Project + Interpretation is that the requirement for Multipole OCPDs came _AFTER_ the Plans had passed Plan Check, and the job was fully into Rough.
I had no idea about the Interpretation, until our Field Superintendent on the Project called me for verification of the Article!
He was informed by one of the other E.C.s on the Project per this issue for MWBCs:
"Either use Multipole OCPDs, or run everything as Two-Wire Circuits!"
Two-Wire Circuits are definitely out! Most Lighting Circuits are in Wireways, and current design has maximum of 28 CCCs in any of the Wireways.
Other reasoning is Homeruns.
I just would have liked to know from the DBS that they would be changing to the 2008 NEC, and will enforce that version in the field.
Then I could have arranged with the Panelboards & Gear Vendor / Supplier to reconfigure the Lighting MWBCs.
I sent an RFI to the Vendor regarding the issue, which was promptly sent back to me - with instructions to contact the Project Manager of the E.C. installing the Panelboards + Gear (AKA: Pass the Buck!).
Bounced same RFI to that guy, and received a "You Are Responsible Now" message for reply!
To rectify the issue, we will be installing Approved Handle Ties (Manufacturer Accessories) instead of replacing with Multipole Breakers.
This is an acceptable method per the Article.
FYI:
I do not have the 2008 NEC, which made things very difficult to verify!
California is using the 2007 CEC (California Electric Code), which uses NEC 2005 as Model Code.
To verify the Article, I researched it on the NFPA site.
According to the NFPA site, the Article's intent is as it always has been; to eliminate the Shock hazard of leaving one or more Ungrounded Conductors live on a Single Yoke or Single Piece of Equipment.
Nothing in regards to Open Common Grounded Conductors (Open Neutrals), nothing about multiple Junction Boxes.
Even the first response from the DBS verifying their stand on the Article, had the same text as the NFPA site did, verbatum! (the text was copied / pasted!)
The problems with interpreting 210.4(B) this way are:
*1: Electricians not turning off Circuits to work on a Fixture or Device,
*2: Installing excessive Conductors to eliminate the need of Multipole OCPDs.
Examples:
*1:
Turning off a Multipole Breaker on Lighting Circuits would result in wide spread darkness, not just in isolated areas.
Turning off a Multipole Breaker will de-energize Receptacles on different Circuits than the one to be serviced.
Results: complaining Customers, personnel encouraged to work things Hot, rather than turn off Circuits (even though there is no justifyable reason to work the Circuits hot!)
*2:
Instead of using MWBCs connected to Multipole Breakers, some may decide to install all Branch Circuits as Two-Wire (L-N) Circuits, using anywhere from 200% to 300% more Copper Conductors than necessary;
AND-
Creating derating issues, as each Circuit will have 2 CCCs.
OK, ranting is over!!!
< RANT MODE = DISABLE >
Scott