Sleeving Flex inside PVC

[mhulbert]

I have a bit of a theorietical question, though I'm sure this is done a lot.

Would it be legal to fish flex (or MC, LTFMC, ENT, etc) through a run of Sch 40 PVC? Say for example, you had a feeder from one building to the next. Said feeder had extra room (per fill calcs) and you fished flex or ENT in it, and pulled a fiber optic cable into that raceway? Would it make any difference what was in that raceway? (ie light /Power, Class 1, 2, 3, comm, etc?) Also, due to it not being a wet loc, would this be acceptable for aboveground?

Not planning on doiing this, but the thought occured to me in a church basement the other day. They had a 4" PVC underground run, and I was wondering how many different systems you could put in the conduit if they are fished in seperately.

Thanks,
Mike

 

[charlie]

Re: Sleeving Flex inside PVC

IMO you can put as many smaller conduits as you can get into the larger conduit but you will not be permitted to install any conductors in the large conduit. Each smaller conduit would then be considered to be a separate raceway. The larger conduit would just be a chase.

If you ever consider doing this, again IMO, the conductor derating would have to include all the conductors in all the raceways combined. The alternative would be to use the Neher/McGrath formulas with engineering supervision. The reason for this is the inability of the heat to escape. The chase, after all, is still a conduit.