PVC duct bank question.
(I have already been looking but can’t find a reference to this.)
Is there a mandate or a code requirement in NEC 2005 that requires that I put chairs on PVC in a duct bank?
- (5) Five feet deep
- No concrete
- 6” sand envelope (bottom, top and sides).
- (8) eight 2” PVC with 3 phase 480 feeders
- Located under building pad.