Joe,
Thanks for the kind words! And also for picking up on the NM-B mistake I made
I so rarely work with Romex, that I neglected that important temperature ID !!!
Mr. Brooklyn,
Glad we all could help out here! If you are using AC or MC [AKA "BX"], the same goes - 2 or 3 wire with ground.
All the MC cable I have worked with lately uses THHN cu conductors, and of course have an insulated grounding conductor [sized per NEC 250].
Steve,
I know that you know what's up with the oversized common grounded conductor in the MC cables you speak of. This would be the few places where inbalanced and excessive load currents would be accepted, as Don [resqcapt19] mentioned.
The triplen harmonic currents would only be in the common grounded conductor, so the best thing to do is increase the ampacity / size of said conductor.
I have no idea where, or if, an increased size common / neutral could be used on multiwire circuits per the NEC - such as using a #8 THHN common neutral with two multiwire hots [2 Line A, 2 Line B, 1 phase 3 wire system].
This would be where Scott W is going with his message.
It would work, but it sure looks suckee!!! [in my mind, that is].
It would work on simple Linear and balancable loads, but what a nightmare if there was any high level THD!!! Seems that even Squirrel Cage Split Phase Induction Motors on these circuits, running at varying loads, would reflect some high levels of double frequency pulsation and resultant harmonics!
Just my opinion only! Please be kind in flamed responses
just tossing out some ideas and stuff to discuss.
Scott SET
P.S. edited some bad spelling
[This message has been edited by Scott35 (edited 09-27-2001).]