ECN Forum Forums Code Related Discussion NEC & other Code issues Multi wire circuits

Hixson was the fellow who trained me. He is a legend around here for many reasons other than being the best d@mn electrician in Greenbrier County. Caving was his true love, and took up the better part of his time. He is now aging, in bad health and lives with me now. My wife takes care of him, but it's the least we can do for the man.

I apologize for mentioning him as if eveyone here knows him, I'll try to be more contientious.

Someone was apparently in court with the PoCo because of burnt-out appliances and Hixson was called in to testify to the court on how this happens.

I figured I could avoid liability by avoiding the use of multiwires in residential work.

Sparky66
Thanks for that clarification, I even had the wrong name listed in my question.
-Mark-

I heard they may make you put multi wire circuits on a 2-pole breaker. So people don't get a false sense of security, when they flip 1 breaker off, and then get zapped by the neutral from the other device. It would also make sure the 2 circuits are on opp. phases.

I use em, because my company does for Disp/DW. But don't like em.

Nothing wrong with multiwires when installed correctly. Although I always use a double pole breaker with them even thought the Code doesnt require them. Maybe it should....

This is a very old argument and we won't settle it here. But that won't keep me from offering an opinion. I do not believe we can or should be building electrical systems to be worked on by unqualified persons. Failing to take advantage of the labor savings available in using multi wire branch circuits is either going to cost you work or income or both. People who will not take the time to understand multi wire branch circuits should keep their fingers out of electrical work.
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Tom

In commercial It may be a different story.
But in residential a bag of 14-2 cost $15, and 14-3 cost $30. So not much money saved there except time. And that money is ussually burned up when you have a rookie sit there and stare at if for 30 minutes on the finish.

Andrust:
I can argue that point, if you got two circuits to run 60 feet and 25 joist to drill through and can run a multi-wire instead sure sounds a whole lot quicker to run one multi-wire then having to run two single circuits.
I use them all the time its just when the DIYer gets hold of them that there seems to be problems with them, ie back fed breakers, because they added a circuit and didnt understand why a red wire was there instead of two blacks.
Its really a nice way to balance loads when done right.
-Mark-

For safety one should use a double pole breaker, but then ...

when one circuit trips the other one does also.

I believe a double pole {or handle tie} is code for a residential multiwire.
It won't matter here, as the AFCI's are all 1-pole, so multi-runs are out for now.

sparky,
I think it's (still) only required to be double-pole if you are supplying 2 devices on the same yoke with a multi-wire.