O.k, but remember you asked for it!! LOL....

First off, may I direct everyone's attention here:

https://www.electrical-contractor.net/ubb/Forum2/HTML/002445-2.html

(Third post down on that page)

'nuff said there, pretty much sums up my feelings about this whole thing. [Linked Image]

As for the original post on this thread, I quote:

Bold emphasis mine...


Quote
Lets say you run 12/4 w/ground and use 3 as hots, 1 as neutral and 1 as ground. The three hots all go to 20 amp breakers. Two of the three circuits will feed out to my kitchen countertop required small appliance branch circuits (GFI protected). The other circuit will be a dedicated receptacle for a plug and cord garbage disposal. At what point do I know that I am overloading the neutral? What are the rules about how many circuits you can run off of one neutral?


As I read this, if this is a single phase residential panel, it would be impossible for all three hots to be on opposite legs (or phases if you prefer) in this application. Thus the certain possibility or neutral overload exists!!!

And isn't 12/4 NM configured as two hots (red/black) two neutrals (white/white with tracer) and ground?

Finally, we have the original poster, an experienced electrician as near as I can tell, about to set himself up with a possible Code violation(if the cable/conductors are not approved to be re-identified as in this application) at least and a fire hazard at worst? (Not trying to put down anyone here, either.)

As in the rant I referenced in the link, even those experienced in the field can be tripped up by the use or mis-use of multi-wire or shared neutrals.

And while individual experiences vary, most of mine with multi-wire have been to fix trouble caused in one way or another by the lack of dedicated neutrals. (I won't enumerate them here, but I have made several posts in different threads re this subject.)

In fact, the original wiring to my apt. was only TWO circuits, one 15 amp lighting circuit and one 20 amp circuit for ALL of the non-lighting loads!! It was served by an very old style of romex with (I'm not making this up) one #12 hot, one #14 hot, one #12 neutral and one bare #16 ground.

That got replaced with all new wiring after the original neutral connection at the split to the respective loads (in a 4s box in a 2nd bedroom receptacle) began to fail with my $5,000 worth of A/V gear energized. I caught it first with the voltmeter in the rack, then my Fluke 36 (after things had cooled down a bit) showed over 158 volts to the recept.

Now all circuits have their own neutral all the way back to my nice new SqD panel. [Linked Image] And not a lick of trouble since.

You did ask... [Linked Image]

edited to fix html...

[This message has been edited by mxslick (edited 05-10-2006).]

Stupid should be painful.