[FlintMich]

Hey guys - been a long time. Finally getting around to running electrical in my pole barn. I'm trying to lay out the conduit before I start to install any EMT but to be honest, it's a bit overwhelming (can anyone say "overthinking it?) and I'm in one of those "analysis paralysis" moments. I just don't want to run a bunch of EMT only to find out that one run needs to be on the other side of another run - if that makes sense.

Maybe it's just me but there is something intoxicating about looking at a beautifully laid out and executed conduit job. And then, on the other end of the spectrum is what my stuff usually turns out looking like. :vs_poop:

Is there a method or a system for laying it out first before ever bending any EMT? I know it sounds silly to ask but it's been stressing me out. It doesn't have to be perfect but I don't want to be embarrassed every time I look at it either.

Any thoughts or suggestions are greatly appreciated. Like I said, I realize I'm probably overthinking this. I just want to do it right the first time. Just looking for some experience driven insight. Worst case scenario, I'll just start installing and deal with it. :wink2:

 

[Datawise]

What I teach my apprentices / students to do is work it out backwards. What do I mean by that? On paper, layout your furthest device / load and work backward from there. As you move closer to the panel your conduit sizes will typically increase.

I generally like to run down the centre of the barn / warehouse with an oversized conduit or two and strategically put oversized junction boxes to take smaller conduit runs out of. If however I have a bunch of items on one wall and a bunch of other on an opposing wall, then I might run two separate “main” conduits closer to each wall and tap from there. A lot depends on construction / layout.

There is no right answer for this. All you can do try to plan ahead, try not to criss-cross your runs and don’t run the smallest conduit.

Cheers
John

 

[rjniles]

There are special considerations if you will have animals or hay/grain storage.

 

[seharper]

"No more than four" circuits per conduit (of any size). DO NOT run 1" conduit and try to put 11 circuits in there! Four keeps you within thermal limits.

Also, for 1/2" conduit, four usually keeps you within fill limits of 9 wires for <=20A circuits (remembering EMT conduit is the ground wire), so that gives you 3 simple circuits and one 120/240.

However, if your circumstances allow multi-wire branch circuits, an MWBC counts a 1 circuit, even though it gives you two effective circuits. However that means as many as 12 wires in the pipe, so you'll want 3/4" pipe.

Speaking of MWBC, you know the thing where you can't use MWBC anymore because of AFCI/GFCI rules? Well, in EMT conduit, the AFCI/GFCI can be at the first receptacle location! Win!

Don't run grounds plural. You don't need to run any grounds at all, but if you're worried about a pipe parting due to physical damage, feel free to throw 1 ground in there connecting the boxes.

Also, be generous with your pulling points. Put junction boxes anywhere you might reasonably expect to want to tap off the system. I recommend junction boxes, not "T" conduit bodies, because you can splice in a junction box, not in a conduit body.

One of my favorite tricks is to run 3/4" double conduit linking 4-11/16" (120mm) junction boxes. That allows 4 circuits *per pipe*, so 8 circuits, and enough room in the big box for pass-through + a couple of taps/splices.

I would generally run them along the eave, up high, with a junction box every 20' or so.

I am not ambitious when it comes to bending. I don't like fidgety bends that have to be precise. Let's say I come out of a panel to run along a joist, and it's exactly 22-9/16" from the panel surface to the joist. I can handle a number-crunch, but y'know what? You don't risk any material if you don't gamble. I cut the piece long on purpose (say, 24"), then fit it up, mark it and cut the excess. See? No precise fitting. Aim to have a leftover piece you can use for something else later. If the same piece needs a second bend, hey - I'll just put a coupler there (or better, an access point!) and pull the same trick.

As long as you have no more than one "90" between access points, you don't even need to pull, per se - you can usually just push the wires through.

 

[Kevin_Essiambre]

What I teach my apprentices / students to do is work it out backwards. What do I mean by that? On paper, layout your furthest device / load and work backward from there. As you move closer to the panel your conduit sizes will typically increase.

I generally like to run down the centre of the barn / warehouse with an oversized conduit or two and strategically put oversized junction boxes to take smaller conduit runs out of. If however I have a bunch of items on one wall and a bunch of other on an opposing wall, then I might run two separate “main” conduits closer to each wall and tap from there. A lot depends on construction / layout.

There is no right answer for this. All you can do try to plan ahead, try not to criss-cross your runs and don’t run the smallest conduit.

Cheers
John

Judging by his username, he is probably on the NEC... which IIRC means that he will have to use some pretty big wires. I know our code, not theirs...


This is the best advice though for minimal conduit runs. It's the same way I lay out runs. If OP wants to avoid de-raiting he would need several small conduit runs.

I'm glad we have a different code...

Sent from my new phone. Autocorrect may have changed stuff.

 

[Reddog5522]

cant splice in conduit body???? code please Seaharper. they are usually identified by ci. and u can splice in them

 

[Jim Port]

Won't be able to find an absolute prohibition against splices in conduit bodies. If marked with cubic inch capacity you can, but probably won't want to.