What section of the NEC covers wiring methods inside large, walk-in air handlers? 300.22 does not seem to apply (I don't have my codebook with me so I trying to do this from memory).
300.22A doesn't for obvious reasons.
300.22B doesn't seem to since the prewired motors inside are fed with nonmetallic sheathed metal flex (not allowed in a duct or plenum due to their potential as a product of combustion and possible contributor of smoke).
300.22C doesn't seem to since, according to the handbook notes, areas manufactured specifically for air handling don't apply.
Inspectors at numerous jobsites are allowing set-screw emt connectors and metal sealtight inside these large units. They also aren't requiring duct-seal or other type of air stop where conduits penetrate the unit (thus allowing air to blow out of these pressurized rooms). Every other seam or door is fully sealed.
The pre-wired motors don't have disconnects within site of them and (as stated previously) are fed with metal sealtight. Can the rest of the motors be wired the same? How can I get by with adding a product of combustion to a duct/plenum and not having a motor disconnect within site?
Can sealed, plastic cased, fluorescent lights be used inside or are "jelly-jars" on metal boxes needed? Are set-screw fittings ok? Don't the penetrations need to be sealed?
Thanks.
