725.136

[Kobe85]

I have a bunch of 120V contacts (will use THHN) and one RS485 signal that I need to wire between enclosures. Issue is I would like to run them in one conduit, if possible.

The RS485 will be run using Belden 3105A - 65% covered copper braid.

I'm looking at NEC 725.136 and the exceptions for having these signals in the same conduit.

I believe, and looking for your opinions, that it appears exception I2 I can run the Belden cable in the same conduit as the 120V contact signals using flexible tubing (some nylon wire loom) to cover the RS485 cable.

Do you agree?

I first thought the copper braid was enough to cover exception I1, but a CSA inspector disagreed.

Thanks for help.

 

[petersonra]

I think claiming nylon loom as a barrier is a bit dubious, but you might win the argument over it eventually. However, I think smurf tubing would qualify, as would a garden hose.

I don't think you can claim a braid as being metal clad. However, they do make metal clad cable that might be the simplest thing to use for you rather than screw around trying to do it cheap.

 

[Kobe85]

I'm fairly certain I could get away with it, but my electrician told me to stick it and he wouldn't want to pull it through conduit, so we did a separate run.