Raceways and Ductwork

[glukonic]

I have a round air duct spanning a roadway at an industrial plant. The duct supports are 50' apart and I need to run two small (1") conduits across the same span. Can I support those conduits from the duct? Someone I work with thought that there was something in the NEC prohibiting supporting conduit off a mechanical duct, but I have been unable to find it.

 

[Len_B]

Re: Raceways and Ductwork

glukonic,

I don't believe supporting conduit from a mechanical duct is strictly prohibited by the NEC. The opposite, using the conduits for support of a duct is not allowed. Your proposed installation may be prohibited by mechanical or civil code, especially over a roadway(public or private?). I am assuming, from the 50' span, that this is a fairly large air duct that would not be compromised structurally by the addition of the conduits. 1" RMC will require supports every 12 ft.

Len