Volta
Senior Member
- Location
- Columbus, Ohio
I had my continuing ed. class today. I like it when the instructor is experienced in the trade, knows his code, and is willing to discuss the topics. This was a good guy on all counts.
He brought up an interpretation of section 300.20(A) that I have never heard. He believes that - and I'll paraphase and leave out some of the code text here:
~To accomplish arranging ac conductors in ferrous raceways so as to avoid heating the surrounding metal by induction, all phase conductors shall be grouped together.~
means taping the conductors every foot or so while pulling them in.
After my initial disbelief abated, I thought that, maybe, I could kinda sorta see where one could see that reading.
Keeping conductors of the same circuit in the same raceway is already covered pretty well in 300.3.
Keeping the wires in a single hole in box entries is 300.20(B).
Could he be right? (I hope not.)
There are some obvious disadvanteges to this practice: withdrawing a conductor, different lengths needed around bends per wire, effectively making a larger diameter unsheathed cable which should affect the fill calc's.
I think the intertwining of multiple circuits' conductors would be only negligable in the induction produced, but what do you think?
He brought up an interpretation of section 300.20(A) that I have never heard. He believes that - and I'll paraphase and leave out some of the code text here:
~To accomplish arranging ac conductors in ferrous raceways so as to avoid heating the surrounding metal by induction, all phase conductors shall be grouped together.~
means taping the conductors every foot or so while pulling them in.
After my initial disbelief abated, I thought that, maybe, I could kinda sorta see where one could see that reading.
Keeping conductors of the same circuit in the same raceway is already covered pretty well in 300.3.
Keeping the wires in a single hole in box entries is 300.20(B).
Could he be right? (I hope not.)
There are some obvious disadvanteges to this practice: withdrawing a conductor, different lengths needed around bends per wire, effectively making a larger diameter unsheathed cable which should affect the fill calc's.
I think the intertwining of multiple circuits' conductors would be only negligable in the induction produced, but what do you think?
