Quote Originally Posted by Chris Padilla View Post
Steve,

Electricity in general is dangerous if things are done incorrectly. Perhaps MWBC are "more" prone to being wired improperly or handled improperly? I did the search and found a link describing how IF THE NEUTRAL was disconnected and how long would a TV with 240 V across it burn up? I guess I can see that. Perhaps someone is working on a receptacle on a MWB and removes it temporarily or something. If that receptacle wasn't wired pigtailed, I guess that neutral could be disconnected. I can see in 3-phase that if the wrong neutral is picked to add a circuit too and if the circuit isn't fully shut down that an over-voltage condition can exist.

But again, if things are done wrong, then sure, things could go awry quickly. An open/disconnected neutral is an extremely dangerous condition and I can see how it would be more so in a MWBC. I can see how things in MWBC can go awry more easily than in other situations.
You've got it right with the neutral issues, Chris. An open neutral can create all kinds of dangers as electricity is seeking the easiest path to ground. Of all the stories I heard and of all the things I personally experienced, the open neutral got the most attention. If you have 2 hots sharing 1 neutral and the hot wires are landed on single pole breakers, you have to know to turn off both breakers before tampering with the wiring. Usually the breakers would be one on top of the other and easy to identify, but I've seen many instances where they are separated and even being on opposite sides (though not directly across from one another, I hope). Every time I trimmed a panel, I would tape the hots and their neutral (single phase or 3 phase) together where the conduit entered the panel, just in case someone later came back and moved the breakers around. Most of the electricians I worked with did the same thing because we all knew how much potential havoc and danger there is with open or crossed neutrals.