[Squatch]

So, I'm wiring up my shop. It's a Quonset style building with no internal support structure. I'll be running emt. I'd like to suspend the junction boxes between the "ribs" then run conduit between them down to a box for the outlets. Does the junction box need to be supported. I read a clip about it being ok as long as the conduit screws directly into the box. I believe they mean ridgid or even pvc but not emt. It'd just be easier if I didn't have to run extra supports for the J boxes. Thanks.

 

[Arrow3030]

There are too many specific requirements when using emt for me to remember off the top of my head. My first thought when seeing the project was to recommend T condulets.

 

[MrElectricianTV]

So, I'm wiring up my shop. It's a Quonset style building with no internal support structure. I'll be running emt. I'd like to suspend the junction boxes between the "ribs" then run conduit between them down to a box for the outlets. Does the junction box need to be supported. I read a clip about it being ok as long as the conduit screws directly into the box. I believe they mean ridgid or even pvc but not emt. It'd just be easier if I didn't have to run extra supports for the J boxes. Thanks.

Offhand I can't think of any instances like yours where the box would be permitted to be supported by conduit only. You need to support the box.

 

[Squatch]

There are too many specific requirements when using emt for me to remember off the top of my head. My first thought when seeing the project was to recommend T condulets.

I didn't think of that. I think that might work, thanks!

 

[Arrow3030]

So it only gets real complicated when you want to put a device or luminaire on an unsupported box. The box's need threaded hubs and each conduit needs to be supported within 3' of the box. This is the same rules for a T condulets BTW. Reference 314.23 (E) NEC 2011

 

[Squatch]

Ok I like the Condulet idea a lot, but after talking with a journeyman and an electrician we all agreed it might be a little too flimsy when used with emt. If I was using rigid or even pvc it probably wouldn't be an issue. Here's what I came up with. I mocked this up tonight. I'll need to swap around my unistrut I've installed, and I don't particularly like how it looks. It's a difficult building to wire. I'll come out the back with a 90 and go down about 4' to a duplex.

 

[Arrow3030]

Yeah that's not so good looking. The T's would look the cleanest. Not sure how PVC would be more stable than EMT. If you really don't want the T or the bell box I'd rather see the box mounted on the part sticking out and doing a 90 with a kick going down the deeper part. I can explain that better if curious.

 

[Squatch]

I think I get what you're saying. Not sure my pipe bending skills are that good. Haha.

I almost thought of mounting the box between the ribs and using 45 degree fittings to help enter the box. It'd be cleaner and I'd just have to make a one bend in the conduit.

 

[Jim Port]

I would vote for running on the flats instead of be tween the ribs.

 

[mm11]

I second Jim. Use T condulets and drop down the ribs with Minerallacs to support the EMT; tech screws and washers to support the boxes. I would not use strut to run one or two raceways around the walls- minis are a lot cheaper.

 

[Squatch]

Ok, I think I've got this figured out. Mounting the J box like Arrow suggested looks decent. I'll bend a piece of conduit to run between the ribs and down to the outlet box and I'll use the Minerallacs to secure the conduit for that run. I'm used to using unistrut as I work in the industrial field and have a large cheap supply of it. I need to move some of my struts I already installed so I fall within code for support, but I feel better about the conduit install now. I'll hopefully have a good deal of the conduit ran this weekend as soon as I fill the propane tank for the shop. It's cold out there! lol

 

[Arrow3030]

Right on. You're going with the 90 and a kick right? Looks like each drop is a duplicate so you should be slapping em up once you get going. You might have to burn a few sticks to get it just right but I'd recommend making the kick angle with the conduit on the floor and stopping the bend when the benders handle is plumb with the floor. This is usually a 30 degree angle but might be a 45. This makes duplicating the angle pretty easy. Keep track of how far from the 90 your arrow is so when you find the sweet spot you can duplicate that measurement. Making sure your box is the same distance from the rib will help keep things flowing too.

 

[Squatch]

Did some bending today, I think I've gotten it...





I went ahead copied it for the remainders..

 

[Arrow3030]

Looks good from here! My only gripe, it's petty, is it looks like you used a sharpie for your bend marks. The box offset on the bottom could be much tighter too...all around good though

 

[Squatch]

Thanks!

LOL, I haven't cleaned up the sharpie lines on that one.. haha!

Not sure what happened on the offset for that one, the others aren't quite as bad and I did a better job with the conduit for the main run's offsets. If I did this all the time I'd buy one of those nice offset benders. lol