Only One Conduit

[Swanton_tech]

I need to run 120 vac L-N-G from one enclosure to another within an existing conduit.
There is a 24 fiber cable and 2 class 2 signal wires in this conduit.
The conduit is a 2 inch PVC and the fiber cable is 1/2" in dia and the signal wires(24vdc)
are 1/4" in dia..
Can I run the 120 vac service through this conduit inside a run of liquid tight or use mc
cable or can I not do this at all?

 

[John Valdes]

You may be able to run this ac circuit with the com cables but I would not do it personally.
I think if the com cables insulation rating is the same or higher as the ac conductors you can run them in the same conduit. I am not certain and someone with more knowledge may have further comments.

I do not like to mix cables like you describe in a common raceway with power conductors.

 

[charlie b]

You are allowed to have conductors of different voltage classes in the same conduit, provided that all have an insulation rating at least as high as the highest voltage represented within the conduit. Reference 300.3(C)(1).

That said, I can see two possible problems. One is that mixing circuit types can cause one to interfere with the other. For example, a power circuit may cause problems with a signal circuit. The other is the whole idea of installing a new set of conductors in a conduit that already has conductors inside. Pulling one past the other may cause damage to either or to both. So if you have to use the existing conduit, you might want to consider pulling out the old, and pulling the old back in together with the new.

 

[Swanton_tech]

I meant to also state that the distance will be no more than 5 feet that the fiber, rs-485, and 120 vac will be in the same conduit. Does anything from nec 2002 (only one i've got) 725.55 on 70-570 apply?

 

[don_resqcapt19]

You are allowed to have conductors of different voltage classes in the same conduit, provided that all have an insulation rating at least as high as the highest voltage represented within the conduit. Reference 300.3(C)(1).

Charlie,
He said he had a Class 2 circuit in the raceway. The FPN after the section you cited directs you to Article 725 which will apply to this installation.