Rigid metal conduit to EMT

[bluedog225]

I am routing AC power from an inverter located in a shipping container, using underground conduit, into my workshop. The run transitions from the inverter through 2-inch underground conduit and stubs up at a 10-inch-thick concrete wall.

My plan is as follows: transition to 2-inch rigid metal conduit (RMC) on the exterior of the wall, run vertically up the wall to a Type LB conduit body (with back outlet), then install a ****** through the wall penetration. On the interior side, I require a sharp 90-degree turn to align with the direction toward the subpanel, followed by a transition to 2-inch electrical metallic tubing (EMT) for the remaining run.

I am wondering whether installing a second Type LB conduit body on the interior wall surface—connected to the protruding ******—represents the most straightforward way of achieving this 90-degree directional change with 2-inch compression-type EMT connector.

I don’t seem to be able to find a tight 90 rigid elbow but another LB is no problem.

Any ideas on how to do this welcome.

Thanks

 

[bluedog225]

Something like this could work. Of course, I find it just after I posted. Though it will still too proud of the internal wall. I think an LB would work better.

 

[Bert_]

Run the outside conduit higher and go right into the back of the sub panel

 

[Steve W.]

Run the outside conduit higher and go right into the back of the sub panel

What if that 90° turn was sideways, not up?

.

 

[dscheidt]

there are not tight 90s because wires have minimum bending radii, typically between four and six times the OD of wire. Note that's a static bending radius, where the wire is folded into place, as in a conduit body or box. Where the wire is pulled under tension, like in a 90 in conduit, the limit is a bigger radius. Big conduits usually have big wires in them...

A conduit body or a big box is the way to go, if you can't do what @Bert_ suggests. Depending on what wires you're dealing with an oversized LB might be the way to go.

 

[Bert_]

What if that 90° turn was sideways, not up?

.

Maybe, want to place bets?

 

[yatg]

I don’t seem to be able to find a tight 90 rigid elbow but another LB is no problem.

You're looking for a 2" RMC pull elbow.
But they're hard to find and expensive because they're not common.
Go with an LB or SLB.

1" pull ell

 

[BurtEggley]

why can't he just use a box on the inside? Or a Bell Box on the outside and a regular box on the inside?

 

[bluedog225]

Thanks guys. I was thinking I’d need to have a threaded fitting. A box hadn’t occurred to me. Just a junction box and punch a hole for 2” rigid and secure with a nut? And size the ****** so the box is tight on the wall?

I realized this afternoon that I wouldn’t have room to turn the LB and screw it in on either side of the wall.

 

[bluedog225]

Run the outside conduit higher and go right into the back of the sub panel

There’s too much in the way. Poor planning. The location of the power source changed.

 

[dscheidt]

Thanks guys. I was thinking I’d need to have a threaded fitting. A box hadn’t occurred to me. Just a junction box and punch a hole for 2” rigid and secure with a nut? And size the ****** so the box is tight on the wall?

I realized this afternoon that I wouldn’t have room to turn the LB and screw it in on either side of the wall.

EMT fittings have the same threads as RMC does. EMT gets screwed into rigid fittings all the time.

As for the box, you’ve got it right. Box needs to remain accessible, can’t bury it in the wall. What size wires are you running? For 2” conduit , I’m assuming pretty big. You may need a bigger box than you think.

 

[bluedog225]

EMT fittings have the same threads as RMC does. EMT gets screwed into rigid fittings all the time.

As for the box, you’ve got it right. Box needs to remain accessible, can’t bury it in the wall. What size wires are you running? For 2” conduit , I’m assuming pretty big. You may need a bigger box than you think.

I didn’t’ know they had the same threads. Makes sense. A box on the inside wall is no problem. And makes things much easier.

I ran the conduit at 2” thinking it was on the safe side as I built my solar system out.

It will end up being a 100A feeder to the cabin. I think that translates to three 1 AWG XHHW-2 aluminum — L1, L2, Neutral and one 6 AWG aluminum equipment ground.

 

[Bert_]

There’s too much in the way. Poor planning. The location of the power source changed.

If you have to, put a 12x12 pull box below the panel

 

[alfredeneuman]

EMT fittings have the same threads as RMC does. EMT gets screwed into rigid fittings all the time.

EMT fittings have straight threads, as opposed to Rigid having tapered threads (NPT). The only rigid fitting that has a straight thread is a coupling.