0

I have to run electrical (EMT), network (schedule 40), and compressed air (Rapidair) lines along the walls of my shop. I'm doing this by putting up vertical sections of Unistrut, and attaching the the various conduits to those. You can see how I've begun:

enter image description here

The problem is that if I try to drop conduit down from that junction box, it will interfere with the air and network lines immediately beneath it. I can't just rearrange the stack because no matter what, drops from two of the three lines will interfere.

What's the typical solution to this? Is there some kind of offset mounting? I suppose a bracket that sticks out perpendicularly from the wall would work, but I figured this is a common scenario. What's usually done in commercial installations?

4

Given that the conduit will be out from the wall owing to the Unistrut, I would put a curve on the end of the conduit, or an offset conduit. Like these.

enter image description here

The purple conduit curves up at the very end, and enters either an LB/LL/LR conduit body, or an EMT pull elbow. Both have lids which allow access for pulling. You never drag wire around this corner; you remove the lid and do two separate pulls.

The LB or LL/LR conduit bodies put the long end into the box. An LB conduit body has a door on top where it might interfere with the second conduit run. An LL or LR conduit body will have a door on the front for easier access at the expense of slightly harder pulling.

enter image description here enter image description here enter image description here

The aqua conduit uses an EMT offset coupler to lift the EMT above the other conduits. Then it does an S-curve to get flush to the wall.

enter image description here

Another way is to use a "tee" conduit body on the main conduit.

enter image description here

enter image description here

Do this within 24" of the junction box. You can't splice in a conduit body*, but you can run the wires around the T to the nearby junction box, and splice there. If it's <24", these extra wires in the main do not count toward conduit derate (310.15(B)(3)), but do count toward conduit fill (358.22, which you know about).


* For conduit bodies matching conduit reasonably sized for the wires therein. If the conduit body is outlandishly large, you can do the same cubic-inch calculations you would do on a junction box, if it is labeled for cubic inches. But it wastes the capacity of the connecting conduit if you do.

  • Ah, this is a good solution, and one I wish I'd thought of before the store closed and I can't get right-angle fittings now. :) – Rick Jul 4 at 6:14
  • I see now you said LB conduit body. Would it be acceptable to use a right-angle liquid tight fitting? The equipment it’s connecting to has liquid tight flexible conduit coming off it. Maybe just too hard to pull through? – Rick Jul 4 at 6:22
  • 2
    You have to feed it very carefully through those. They also make corner 90s with the lid on an angle, those will work too. – Harper - Reinstate Monica Jul 4 at 6:54
  • Those liquidtight right angles can only be used right at a box entrance. I've edited my answer to show alternatives to those. – Harper - Reinstate Monica Jul 5 at 16:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.