Receptacle MWBC OPD

[Joethemechanic]

I have some 100ish foot runs of MWBC that originally had a mix of 240 and 120 single phase receptacles. I'm replacing all the devices with 20 amp 120 duplexes because I have no need for 240 single phase receptacles. Does the breaker need to be common trip or can it just be handle tied. I'd really rather not have them both trip if there is only a problem on one phase. But I defiantly don't want to pull a 2nd neutral

 

[wwhitney]

An MWBC that supplies only line to neutral loads may use two handle-tied single pole breakers. If the MWBC supplies more than one load and supplies any L-L loads, then it needs a double pole breaker, per 210.4.

Cheers, Wayne

 

[Joethemechanic]

one load

Multiple receptacles are considered "one load" by NEC definitions?

 

[wwhitney]

Multiple receptacles are considered "one load" by NEC definitions?

The actual language is "one utilization equipment." Multiple receptacles would be the opposite, you could plug in multiple pieces of utilization equipment.

Cheers, Wayne

 

[wwhitney]

The conclusion for your situation is that when the MWBC had both 240V and 120V receptacles on it, it did need a double pole breaker. But now that it has only 120V receptacles on it, you may change it to two single pole breakers with a handle tie.

Cheers, Wayne

 

[don_resqcapt19]

I'd really rather not have them both trip if there is only a problem on one phase.

The other breaker may or may not open when one breaker of handle tied pair trips.

 

[retirede]

The other breaker may or may not open when one breaker of handle tied pair trips.

To add - even if one doesn’t trip, it will need to be switched off in order to reset the one that did.

 

[Joethemechanic]

It originally had fuse panels for lighting and receptacles when I bought this place over a decade ago. I installed 20 amp doubles because when I replaced it because of the 240 single twist locks in every other box along the wall. But in over 10 years I've never had anything 240 single phase that I needed to plug in. And more 120 volt locations would cut down on the mess of cords that are just waiting to trip me and break my hip so I can die in a cheap nursing home in a soiled diaper

I'm just going to handle tie singles and see if it flies

I should have stuck with fuses

 

[Joethemechanic]

The other breaker may or may not open when one breaker of handle tied pair trips.

I'll just use a piece of that 14 CCA for the handle tie

 

[Joethemechanic]

To add - even if one doesn’t trip, it will need to be switched off in order to reset the one that did.

Nothing but shop tools and small equipment getting plugged in out there, so a momentary power interruption is no big deal