Emergency Generator Exhaust air fan... Wiring in power conduit?

[xnetfly]

I am a design engineer working on a project that has been constructed. I have a question concerning the wiring for an exhaust fan in the emergenerator room.

There is a control circuit coming from the emergency generator to the exhaust fan which is wired in the same conduit as the power wiring for the fan. No problems have been observed for this however just a code question.

What would the control wiring be considered? Class 1 or Class 2? Is this common practice for the emergency generator wiring if not going back to a control system and just directly being routed in the same room from the emergency generator? Does this wire classify as a Class 1 because it is a remote-control circuits to safety-control device (NEC 725.11)

 

[stanlsimon]

When you say control wiring it sounds like the voltage of the control wiring is 24 volt. If so this would be a code violation, the NEC does not allow mingled voltages.

Often times the control voltage can be 120, 208 or whatever to agree with the power wiring. However when using multiple conductors in one conduit the conductors have to be derated. This means that you have to increase the gauge of the conductors, and sometimes increase the size of the conduit.

Simply put, it is easier to hang separate conduits.

Sincerely,
slsimon