ECN Forum Forums General Topics of the Trade General Discussion Area Emergency circuits mwbc extension

I asked this on other forums, would like to hear from here.


Since the 2014 NEC will not allow mwbc for emergency circuits, I assume this will apply to any extension of an existing mwbc. Am I correct in this thinking?

At present there is a small job that wants to add another emergency receptacle and relocate an existing one but the existing circuits are all mwbc. Will this be a code violation to move the existing receptacle that is al ready on the mwbc?

brother:
Could you post where in '14 this is?
I briefly scanned thru '14 and couldn't see anything?
Chapter 5 healthcare? Chapter 7??

It was added to 517.18(A) and 517.19(A) in 2011.
It was added to 700.19 in 2014.

Do it fast before the local AHJ uses the more restrictive rules.

Am I the only one who sees the NEC as moving against MWBC at almost every turn?

What we're seeing is a general push for dedicated neutrals.

Somehow I feel that this is tied in to the pervasive use of back-stabbed R5-15 duplex receptacles in residential builds.

For, at bottom, isn't all of this a concern about breaking open the neutral return?

Ghost:
Thank you!!

brother:
You are using '14 NEC in Tn already??

If you were here in NJ, and extending an existing circuit, it would be no problem, as it would fall under our Rehab Code in the NJ Uniform Construction Code.

Its the place I work at, even if the state hasn't adopted the new NEC, the practice in my place is use the most current one.

I was just curious if others have ran into this yet. I can see getting away with using mwbc for an existing'relocate' receptacle, but if you are extending to a 'new' receptacle it may be an issue.

If the 2014 is adopted and the rehab code says you can, you have a conflicting issue. Usually you would then go with the more restrictive rule