On July 23, 2014 at 14:11, King of typos said...
Meaning what exactly? If you are referring to circuit A coming from Leg A, and circuit B coming from Leg B of the utility power. Then I can understand that. Basically if the neutral would fail for whatever reason, those two devices the dishwasher and food disposal will now have 240 going to them.
If that is the case, then having the breakers on different sides of the panel doesn't make since. As they still can be on Leg A and Leg B. You'll want to have them on the same side, but a breaker for a different circuit between them. So both the dishwasher and food disposal would be on the same Leg A (or B).
I'll have to find my NEC and look that up though.
KOT
In multi branch circuit the neutral (common) carries the unbalanced load.
Remember in a single phase system the Phases are 180 out of phase.
ex.
Black wire (Phase A) = 10A
Red wire (Phase B) = 10A
Neutral = Black Wire (Phase A) Amps + Red Wire (Phase B) Amps
10A + -10A (Remember 180 out of phase) =
0A
Now lets say you put both wires on the same Phase...
Black wire (Phase A) 10A
Red wire (Phase A) 10A
Neutral = Black Wire (Phase A) Amps + Red Wire (Phase A) Amps
10A+ 10A (same phase now) =
20 A
And now you are damaging the neutral wire.This is why it is so important to place the breaker legs on different Phases !!!
