GF Outlet Placement

chris75

No its not. This is a new requirement for the 2008.

Wildie

I confess, I'm unfamiliar with MWBC I would appreciate it if you would enlighten me!
may be good to know when I retire to Florida!

Gigs

Wildie go look at this thread:
Conduit Fill and Derating

Wildie

Thanks for the link Gigs!
This is exactly the way that split receptacles work here!
If a 1000 watt toaster is plugged into the top half, and 1000 watt fry pan is plugged into the bottom, there will be no current in the neutral.
Current will flow from one transformer pole to the other pole. None will flow in the neutral.
Its important that the opposite poles feed the outlet(s).
Otherwise, it would be possible for 30 amps to flow in the 14 guage neutral.
To guarantee that this would not happen, a 2 pole breaker is required, to pick up the staggered poles.

rgsgww

I meant every new installation.

chris75

I'm still not required to do it, my state is not adopting the 2008, so the only time I would need a double pole breaker is when both circuits are on the same yoke of a device.

rgsgww

Well, by the 2008 code cycle. My state adopts the 2005 nec.

Wildie

If your sketch were to be wired to the same pole in the panel, it would be possible for 40 amps to flow in the white neutral.
I don't believe that this would be acceptable in any jurisdiction.
Wiring to a two pole breaker would prevent this as both poles are present on two pole breakers.

rgsgww

But if you have two single pole breakers, side by side, they will be on separate legs. Older panels will be an exception.

Double pole is safer in my opinion, but I don't have to install them.

People rearranging the panel might mess it up.

Wildie

Yes! As long as the red and black are wired to adjacent breakers everything is OK! Electrically!

The danger is if wires are moved to different breakers. Also, someone could assume that the power is off, when one breaker is shut off and the other remains on.

Although the code in your area doesn't require a 2 pole breaker, if someone were injured its a possibility that you could face a lawsuit, for not practicing due diligence as a professional.
Codes don't allow us to avoid responsibility! They just establish MINIMUM requirements!

jamiedolan

I just bought double poles to use, they were only $2 more for a double than 2 single pole. If I was using single pole for a MWBC, I would make sure it was very clearly labeled.

Jamie

rgsgww

I have been swapping out some of the singles with doubles in my main. Much safer, easier to shut off circuit. My state (Iowa) doesn't require it, yet doesn't ban it.