Mutiwire Branch Circuits

[nhee2]

Any reason that a multiwire branch circuit could not feed (2) individual GFI receptacles? Need many outdoor, 20A receptacles for truck parking lot (block heaters). Was planning on 2 gang boxes each with (2) GFI receptacles and trying to limit qty of conductors and conduits required.

Pretty basic but not what I normally do. Assuming its fine code-wise any other reason you would not use MWBC? Accepting that trip of one breaker takes out 2 ckts.

 

[roger]

I'd use MWBC's without hesitation.

Roger

 

[dkidd]

Accepting that trip of one breaker takes out 2 ckts.

You don't need to use 2-pole breakers. Handle ties will do.

 

[luckylerado]

..any other reason you would not use MWBC? Accepting that trip of one breaker takes out 2 ckts.

Will they be switched or will they be on all the time?

Edit: Not sure if it matters considering handle ties or multi-pole breakers.

 

[nhee2]

Will they be switched or will they be on all the time?

Edit: Not sure if it matters considering multi-pole breakers.

They will be (assumed) on all the time - continuous loads.

Thanks for the feedback.

 

[Ponchik]

You don't need to use 2-pole breakers. Handle ties will do.

Even with handle ties when one trips it will open the other circuit.

I guess the good part about handle ties is you can remove the handle and troubleshoot one circuit at a time.

 

[dkidd]

No it won't.

 

[luckylerado]

Even with handle ties when one trips it will open the other circuit.

Not when it trips only when it is manually opened.

 

[ActionDave]

Not when it trips only when it is manually opened.

That is not always a sure thing. Both poles may open on a single pole trip with handle ties. It's a crap shoot.

I would still use MWBC in this case. I've done it before for this exact set up with no troubles.

 

[Ponchik]

No it won't.

HMMMM. I need to try it.

I have not seen a case when one trips and the other does not open with it. Unless if the tie handle is loose.

 

[jap]

I always used to use the MWBC but that was before tying the handles came into play.
I've never been a fan of tying breakers together for a 120v load just because they share a neutral.
Now I seriously consider pulling the extra neutral if it doesn't crowd the pipe or break the bank.
It's sometime worth it to me not to have to hear all the handle tie vs. 2 pole breaker arguments that keep coming up as evident above.

JAP>