No more SHARED Neutrals on Emergency circuits

[brother]

It appears they finally outlawed shared neutrals for emergency circuits in the 2014 NEC. 700.19 states

... "The branch circuits serving emergency lighting and power circuits shall not be part of a multiwire branch circuit.

It also appears they are slowly trying to require some type of emergency lighting in panels rooms, at least for the main disconnecting means. They added to 700.16

... Where an emergency system is installed, emergency illumination shall be provided in the area of the disconnecting means required by 225.31 and 230.70 as applicable, where the disconnecting means are installed indoors.

What do you think of this?

 

[ActionDave]

It appears they finally outlawed shared neutrals for emergency circuits in the 2014 NEC. What do you think of this?

The MWBC is spawn from the loins of the Devil himself. Stamping them out should be a higher priority.



On a more serious note I think if is the progression of things. I predict before my life ends the use of the common MWBC will end. It takes too much effort to teach how to run and work on them and as such there is too much hysteria about them.

 

[roger]

It takes too much effort to teach how to run and work on them and as such there is too much hysteria about them.

Sad isn't it? Just another dumbing down solution to a non existent problem. I wonder someone will try to do away with the normal single neutral service in the future?

Roger

 

[steve66]

Seems reasonable since MWBC's need a common trip circuit breaker. You wouldn't want to trip 2 or 3 emergency lighting circuits just because there is a fault in one ballast somewhere.

Maybe that's all it means, and hopefully its not an indication of more limitations on MBWC's in future years.

 

[texie]

Seems reasonable since MWBC's need a common trip circuit breaker. You wouldn't want to trip 2 or 3 emergency lighting circuits just because there is a fault in one ballast somewhere.

Maybe that's all it means, and hopefully its not an indication of more limitations on MBWC's in future years.

MWBC's don't have to be common trip. Listed handle ties are OK and what I encourage to use as it is less likely for this to happen.

 

[GoldDigger]

It appears they finally outlawed shared neutrals for emergency circuits in the 2014 NEC. 700.19 states






It also appears they are slowly trying to require some type of emergency lighting in panels rooms, at least for the main disconnecting means. They added to 700.16




What do you think of this?

In my customary effort to find another way to interpret code language, I have to ask whether it is OK for emergency circuits to be all of an MWBC rather than just part of it?

It makes some sense that an MWBC should not result in a neutral being shared between an emergency and a non-emergency circuit.

 

[steve66]

MWBC's don't have to be common trip. Listed handle ties are OK and what I encourage to use as it is less likely for this to happen.

My mistake. But I think a similar reasoning still applies - you don't want to have to shut off 3 emergency lighting branch circuits to do maintenance or to work on the circuit.

In my customary effort to find another way to interpret code language, I have to ask whether it is OK for emergency circuits to be all of an MWBC rather than just part of it?

It makes some sense that an MWBC should not result in a neutral being shared between an emergency and a non-emergency circuit.

IMO, the code clearly says no MWBC, regardless of normal or emergency. Besides, the requirement for separate conduits would prevent anyone from sharing a neutral between emergency and normal circuits.

 

[brother]

My mistake. But I think a similar reasoning still applies - you don't want to have to shut off 3 emergency lighting branch circuits to do maintenance or to work on the circuit.




IMO, the code clearly says no MWBC, regardless of normal or emergency. Besides, the requirement for separate conduits would prevent anyone from sharing a neutral between emergency and normal circuits.

Where does it say you cannot use MWBC on all normal circuits? I know it's only limited on some normal circuits but not all, if so show me please.

I remember when I first mention this guy sometime ago and some people thought he was a 'wind bag' lol but it appears he might eventually get what he wants, a ban on all shared neutrals on branch circuits.

http://www.nfphampden.com/mbc.pdf

I wonder what everyone's opinion of this guy is now? It probably will be only a matter of time when they will go after all mwbc on normal circuits too.

 

[roger]

http://www.nfphampden.com/mbc.pdf

I wonder what everyone's opinion of this guy is now?

He's still an idiot.

Roger

 

[wirebender]

He's still an idiot.

Roger

:lol::thumbsup::happyyes:

 

[ActionDave]

Sad isn't it? Just another dumbing down solution to a non existent problem.

I see a future with an electrician sitting in a rocking chair and someone asking him to, "Tell me again how you got three whole circuits to work with only four wires."

"Well, ya' see at one time we could share a neutral, it all started with Thomas Edison...."

I wonder someone will try to do away with the normal single neutral service in the future?

Roger

I frequently get blank looks or eyes averted to the floor from MWBC haters when I mention the fact that all they are is a miniature version of the service.

 

[mike1061]

Another thing that makes us get away from shared neutrals is AFCI's and GFCI breakers.
Thanks
Mike

 

[mbrooke]

I see a future with an electrician sitting in a rocking chair and someone asking him to, "Tell me again how you got three whole circuits to work with only four wires."

"Well, ya' see at one time we could share a neutral, it all started with Thomas Edison...."
I frequently get blank looks or eyes averted to the floor from MWBC haters when I mention the fact that all they are is a miniature version of the service.

Not bashing MWBC, they do have there place but at the branch level a neutral is way more likely to open up, that and the fact the water bond can usually take over should the neutral break open. 2 different things, but the way I see it someone in the code making panel has a beef with them.

About the only thing I agree with and would keep if I had the power to change would be handle ties in resi only. Only because to many homeowners trip a breaker to change an out let or switch and get a nasty surprise. But in commercial and industrial its just stupid. If you cant figure something so simple out than dont touch it.

 

[roger]

but at the branch level a neutral is way more likely to open up,

I can't agree with that. In my 40 years in the trade I have seen far more loose service neutrals cause problems than MWBC neutrals.

Roger

 

[steve66]

Where does it say you cannot use MWBC on all normal circuits? I know it's only limited on some normal circuits but not all, if so show me please.

What I said wasn't exactly what I meant - I was responding to Golddiggers comment:

I have to ask whether it is OK for emergency circuits to be all of an MWBC rather than just part of it?

It makes some sense that an MWBC should not result in a neutral being shared between an emergency and a non-emergency circuit.

I meant no MWBC on emergency circuits even if the neutral isn't shared with a normal circuit.

 

[don_resqcapt19]

I can't agree with that. In my 40 years in the trade I have seen far more loose service neutrals cause problems than MWBC neutrals.

Roger

I agree, that has also been my experience over that same time frame.