I noticed in a foundry that their electric conduits in the ceiling to feed various equipment looked like spegheti. The company would like to run major conduit runs through 2 or 3 large J.B.a spread out all overhead around different areas where you can just pipe up and attach electric equipment hard wired, spliced, and ran through a larger conduit back to the panelboard. There could be a possbility of 10-20 ckts. Does the derating factors of 310-16 apply here, and if so, does this installation warrant???

[This message has been edited by Wirenuttt (edited 11-10-2002).]

welcome Wirenuttt


IMO, derating would apply, T310.15(B)(2)(a) would dictate 50% off of 310.16 ( 10-20 conductors), however note the math starts at the 90degC collum there.

some consideration for the cieling 'ambient' temp may also apply

The interesting thing is the JB vs. a trough, and the magic '29' conductor limit here;