Sharing 120 volt neutrals

[Rlmwireman]

Where does it address this in code?
Next in a commercial job can u share
Neutrals?

 

[electrofelon]

Where does it address this in code?
Next in a commercial job can u share
Neutrals?

'
I assume you are referring to a multiwire branch circuit. See 210.4. No problem using them, but see 240.15(B)(1)

 

[mhanson]

NEC 2017 - 200.4 I think this will answer your questions

 

[infinity]

Where does it address this in code?
Next in a commercial job can u share
Neutrals?

We always used MWBC's in commercial applications unitl the handle-tie/multi-pole CB rule came into play. They're are still permitted in residential and commercial work even though you may hear that they're not permitted.

 

[electrofelon]

The issue with commercial is that three pole breakers are considerably more expensive than three single poles. Some manufacturers make a three pole handle tie but some do not IIRC.

I strongly prefer handle ties so that for trouble shooting and maintenance I can remove the tie and turn only the required circuit off. I have had to work some many things hot with single handle multi poles or factory ties it's frustrating and slow.

 

[mjerney]

I thought the requirement was brought in more for going with the requirements for afci breakers, can't share neutrals with them, unless I'm missing something?

Sent from my SM-N975U using Tapatalk

 

[LarryFine]

I thought the requirement was brought in more for going with the requirements for afci breakers, can't share neutrals with them, unless I'm missing something?

That's an equipment issue, not a code issue.

 

[jmellc]

I never liked MWBC much. Losing a neutral means something gets burned up. When new, it does save a little time to have only the 1 neutral splice but you might start off with 4 wires to a neutral splice, then it’s harder to add a new run to a box later on.

Now a trip on 1 ckt kills other 1 or 2 as well. Hard to explain to a customer why we have to connect the breakers.

 

[Fred B]

I thought the requirement was brought in more for going with the requirements for afci breakers, can't share neutrals with them, unless I'm missing something?

Sent from my SM-N975U using Tapatalk

Some mfg are making a double pole 120/240 afci, are hard to get, likely not finding in big box like Lowe's or home depot. I've installed a few to meet afci requirements when I've picked up behind a gc that started then got in over their heads, so wiring was already run, big headache tracing to find out what was done.
But anyway, Not sure how well they work if loads were severely imbalanced, but I haven't had a callback for nuisance tripping on the ones I've put in.
That is also part of the reason they've come out with the 12/2/2 and 14/2/2 to allow single pull and have 2 circuits, same as doing a mwbc with a 3 wire.

 

[jaylectricity]

I thought you only needed the handle tie if 2 circuits were on the same yoke.

 

[AC\DC]

I thought you only needed the handle tie if 2 circuits were on the same yoke.

Nope Have to "Simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates"

 

[LarryFine]

I thought you only needed the handle tie if 2 circuits were on the same yoke.

It used to be that way; not, it's any MWBC.

 

[jaylectricity]

OK...I need the code number...both for the 2020 and let's go back to the 2014. I'll see if I have a 2014 laying around. I don't remember throwing any code book away, but I don't remember seeing it around my house lately.

 

[hillbilly1]

I never liked MWBC much. Losing a neutral means something gets burned up. When new, it does save a little time to have only the 1 neutral splice but you might start off with 4 wires to a neutral splice, then it’s harder to add a new run to a box later on.

Now a trip on 1 ckt kills other 1 or 2 as well. Hard to explain to a customer why we have to connect the breakers.

Multipole breakers yes, but handleties no, a single breaker triping with handle ties will not trip the other one or two.

 

[AC\DC]

210.4.B for 17 & 20

 

[ActionDave]

210.4(B). It goes back to 2008. I passionately hate it so much it is one of the few code references I know by heart. It's in my top two worst code changes ever. It has caused a horrible waste of resources because everyone specs dedicated neutrals now and is ruining a generation of electricians who have no understanding of a MWBC.

 

[electricman2]

210.4(B). It goes back to 2008. I passionately hate it so much it is one of the few code references I know by heart. It's in my top two worst code changes ever. It has caused a horrible waste of resources because everyone specs dedicated neutrals now and is ruining a generation of electricians who have no understanding of a MWBC.

I couldn't agree more

 

[hillbilly1]

210.4(B). It goes back to 2008. I passionately hate it so much it is one of the few code references I know by heart. It's in my top two worst code changes ever. It has caused a horrible waste of resources because everyone specs dedicated neutrals now and is ruining a generation of electricians who have no understanding of a MWBC.

As with a lot of code changes, it was probably pushed by a manufacture to sell more product under the promotion that it’s safer. Which with the current new crop of electricians..........