inspector

[desertplace]

Hi Mike, i am currently the sole inspector for a casino in upstate n.y. my ques. is on multiple circuits. before i approach the electrical contractor i need some guidance on art. 210.4 and following. it is my understanding that, these requirements need to be meet. even though the circuits here may not be on the same yoke, or strap. i have a hotel -casino in the hotel portion there is 22 rooms per floor all feed from a electrical room on each floor. they are fed with a #8 mc cable 3 hots 1 neutral. all on single pole breakers. it is my understanding that these need to be on a 3pole breaker.

Thanks in advance,
Bill

 

[Dennis Alwon]

If these are truly multiwire circuits and not feeds to another panel then I see no need for them to be on a 3 pole breaker unless they terminate on the same yoke of a device. Would you want the entire area to go out when there is a short or overload on one phase? I don't think so--- Now the 3 single poles must each be on a separate phase otherwise you can overload the neutral.

 

[roger]

I agree with Dennis. There is no requirement for these MWBC's to be on handle tied breakers.

Roger

 

[raider1]

There is no requirement for these MWBC's to be on handle tied breakers.

Yet.....

Chris

 

[infinity]

Yet.....

Chris

Let's hope there never is.

 

[roger]

I agree with Trevor.

Roger

 

[raider1]

Take a look at ROP 2-10

Proposal 2-10 ? Will require common disconnect of all ungrounded conductors of all multi-wire branch circuits installed in all locations.

Here is the ROC for 2-10

Comment 2-10 ? The panel reversed itself on the requirement to identify each grounded conductor of a multi-wire branch circuit. The common disconnect and grouping of the conductors in the panelboard requirements remained.

I may be wrong but it seems to me the CMP has accepted the requirement for a common disconnect for all ungrounded conductors of a multi-wire branch circuit for the 2008 NEC.

Chris

 

[jwelectric]

Hey you all he asked MIKE

Let me say I agree with the rest.

Now Mike has answered lol :grin: :grin: :grin:

 

[roger]

Hi Mike.

Chris, I'm still hoping it falls by the way side. :smile:

Roger

 

[GeorgeB]

Proposal 2-10 ? Will require common disconnect of all ungrounded conductors of all multi-wire branch circuits installed in all locations.

I may be wrong but it seems to me the CMP has accepted the requirement for a common disconnect for all ungrounded conductors of a multi-wire branch circuit for the 2008 NEC.

Chris

The OP does not have MWBC ... each circuit is fed with one phase and one grounded conductor. If a 208 single phase circuit is involved, those (2) would be, and (on a single yoke) need handle tie common trip.

 

[roger]

George, the OP does in fact have a MWBC.

they are fed with a #8 mc cable 3 hots 1 neutral.

Roger

 

[ryan_618]

Hi Mike.

Chris, I'm still hoping it falls by the way side. :smile:

Roger

I don't think it will. I got a lot of support.

 

[roger]

I don't think it will. I got a lot of support.

Darn!

I can still hope, even if it's for a miracle.

Roger

 

[donselectric]

if there is no line to line devices and they run all line to nuet
loads why would you need ties its not a muti wire circuit

jmo

 

[roger]

if there is no line to line devices and they run all line to nuet
loads why would you need ties its not a muti wire circuit

jmo

Line to neutral loads are what make up a MWBC

Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.

Roger

 

[ryan_618]

if there is no line to line devices and they run all line to nuet
loads why would you need ties its not a muti wire circuit

jmo

How would it not be a multiwire circuit?

 

[Shockedby277v]

 

[Shockedby277v]

Why their not sharing neutrals in this picture is beyond me.

 

[ryan_618]

Why their not sharing neutrals in this picture is beyond me.

Because that graphic is showing "multiple circuits", which is what 210.7 addresses. If you look in 210.4, you will find a similiar graphic for multiwire branch circuits.

 

[roger]

Shocked, as Ryan points out, there is a diffence between 210.4 and 210.7.

Roger