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Background:

I'm installing EMT for the first time, in an unfinished garage to replace unprotected semi-random spaghetti Romex runs. THHN goes inside the EMT, and the 3/4" EMT will be attached to the undersides of roof joists to make roughly an L pattern along two sides of the garage. At each of the L ends and the middle corner, I will be mounting metal 4x4 junction boxes to the joist faces.

Issue:

It seems straightforward to me to use a cast 90 degree EMT elbow fitting to connect each straight run end to the junction box mounted on the joist face right above it. However, it seems nigh impossible to locate more than 1 or 2 3/4" EMT cast 90 elbow connectors at local big box stores, chain hardware stores, or even an online supply house I use. The equivalent 1/2" connectors seem to be more available.

Question:

Is there some other EMT 90 degree connection to junction box method that everyone uses, so nobody uses the cast 90 degree connectors and so they are hard to find, or is it just supply chain issues? I thought I had lucked out when I found 5 in one store, but the quality was bad, with casting ridges inside that hadn't been smoothed down.

Here's an example of what I'm looking for: enter image description here

Edit1: As Ecnerwal suggested, "If you are considering these because you are trying to run EMT without a bender,..." the answer is "yes". Sounds like I need to reconsider. BTW it's just a single 20A circuit running through this conduit, but I have ambitions to replace other wiring in the garage if this goes well.

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  • How many circuits of what amperage? 1/2" EMT will do a great deal, and when you need to do more, a second parallel run of 1/2" EMT won't run into the wire derating (thus, oversizing) that cramming a lot of circuits into one 3/4" EMT will.
    – Ecnerwal
    Oct 11, 2022 at 23:50

2 Answers 2

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Those are annoying as <-bleep-> to pull through, so it's better to arrange your runs to have nice easy-to-pull sweeps that you make with your bender (and straight box entries.)

That may involve a different configuration of conduit than the one you have thought up requiring a bunch of sharp turns. It will be more efficient that way. Lacking a picture of what you are doing, I'd say typically coming up from the box with a sweep and running the EMT above the joists would work better - or running the EMT along the top of the walls and then coming out to the face of the joist where you want the boxes. The point is to make the changes in direction in a manner that's compatible with the radius of your bender.

If you are considering these because you are trying to run EMT without a bender, I would suggest re-thinking that course. I'm the odd weirdo who runs all my wiring in EMT even though local code would be fine with NM/B. I've seen too many rodent-skinned wires in remodels and I know better than to think there couldn't possibly be rodents in my house. Learning to use a bender (and adjusting the instructions you can find for doing that if you find their magic measurements don't match what your actual bender does) is, IMHO, essential to effective use of EMT. Then, like anything, practice (and put the first few pieces you bend somewhere they won't be seen after it's done.) You can fix a lot of newbie goofs with a few more cuts and couplings.

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    "(and adjusting the instructions you can find for doing that if you find their magic measurements don't match what your actual bender does)" I've been using the same bender for 57 years, will never get rid of it...
    – JACK
    Oct 12, 2022 at 0:20
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    Likewise, I have a 1/2" and a 3/4" - I just find that they, being older ones I bought used, have some slight differences in where to set them to get the bend you want than whatever default applied to the "how to bend EMT" document I have printed out. It was easy enough to measure what they did and cross out / pencil in the numbers applicable to the ones I have.
    – Ecnerwal
    Oct 12, 2022 at 1:57
  • I don't bother with precise bending skills, I just get within a few inches, test-fit the piece, and cut where the coupler or connector needs to be. It's easier than it seems. Oct 12, 2022 at 3:48
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About 99% of my work is in EMT conduit. I own 10 colors of THHN, none green lol.

Those emergency elbows

The elbows you picked there are intended for absolute desperation situations where you don't have another choice. That's why you find so few of them. The wire cannot be pulled around the elbow - getting it out is an exercise in using pliers. Thus, the wire must be pulled in from the far end, which is straight. You cannot have a run with these on both ends. To load the wires you'd need to disassemble the conduit, and that is not allowed.

Orienting the boxes vertically for a horizontal entry seems elegant, but it's a total fail for buildability.

Instead, simply nail in a "crossbar" 2x4 and mount the box horizontally face-down with about a 1/4" inset so the pipes go into the side of the box perfectly.

Let's review some other EMT 101 stuff.

Number of circuits

First, you can only have four 15-20A circuits in conduit of any size. (240V circuits and MWBCs count as 1 circuit). I wonder why you're using 3/4" conduit instead of 1/2", and if it's to squeeze a ton-pile of circuits, forget it. No more than four, and if you need up to 8, just run two 1/2" conduits side by side. With 30A and larger circuits, the restriction comes sooner and you have to crunch the numbers per NEC 310.15(B)(3)(a), keeping in mind 240.4(D) and using the table at 310.15(B)(16) for ampacities. For 15-20A circuits don't bother; the answer is "no more than 4 circuits".

Now if you need to break the rule, that's fine, but you'll need to use a larger wire size. For instance for 5-10 circuits of 20A, you can use #10 copper.



If you want to use junction boxes merely as pass-throughs, that is fine. There is no practical limit to the number of wires in a box used that way, because it is subject to the conduit body rules. However if you put a splice in the box, it is now subject to the junction box rules which have cubic-inch fill limits, 2.25 cubic inches per #12 wire passing through or being spliced. That limits a 4x4 box to 9 wires. Grounds are 4 for the price of 1, but you shouldn't need any.

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  • Just one 20A circuit, with a splice going to a wall outlet from each box. Thanks to you and the others here for reassurance about 1/2 inch being plenty. Going to 3/4" for the main runs was based on a bit of remembered advice to always go one size higher to allow for future additional runs. I feel belt and suspenders for grounds, so I've got green THHN as well.
    – Armand
    Oct 12, 2022 at 4:10
  • Future additional runs - you can fit NINE 12AWG THHN wires in 1/2" EMT while staying below 40% fill. 4 two-wire circuits plus the ground wire you don't need, 3 MWBCs using conduit for ground, etc. Plenty of room for expansion unless you are expanding into 50A circuits in the same run of conduit. More reasonably, you might think about a 15A lighting-only circuit on 14AWG sharing the run.
    – Ecnerwal
    Oct 12, 2022 at 15:11
  • FWIW, I recently did a large project all in surface mount EMT and even though I could have gotten away with doing a lot of it in 1/2", the extra money I spent on doing it all in 3/4" was less than buying a decent second bender would have cost. That way I can hand bend all the branch circuits, and buy factory bends for the 1-1/2" feeders.
    – Chris O
    Oct 12, 2022 at 16:21

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