Running 240v 50a wire in conduit inside a retaining wall


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Old 03-22-14, 01:29 PM
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Running 240v 50a wire in conduit inside a retaining wall

Is this legal?

I've built a retaining wall, and it's time to fill it with concrete, but first I want to run a 1 1/4" PVC conduit for 6 ga wire through it. Then I can mount an RV outlet box onto the wall.

So, I want to run about 30 feet of PVC and wire through the length of the wall. That means NOT 90° through it, but parallel and INSIDE the blocks, then concrete it in place.

So, is this legal?
 
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Old 03-22-14, 03:59 PM
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Welcome to the forums! Do you need a 50 amp circuit? Most RV receptacles are 30 amps. How do you plan on terminating such a large conduit? Running the individual wires, not cable is doable, after you figure out each end.
 
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Old 03-22-14, 05:56 PM
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Yes, PVC can be encased in concrete. However, I am wondering the same thing as Chandler, how do you plan terminating the conduit to the RV panel? Just come into the side?

Just as a note: 1" PVC should be plenty large for 3 #6 wires and one #10 wire (ground).
 
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Old 03-22-14, 06:04 PM
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The conduit could also be run behind the wall.
 
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Old 03-22-14, 09:18 PM
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I think the plan is definitely do-able, and should work. However, you should check with the local AHJ (building department) to make sure it complies with their requirements. It would be a shame to have to rip it all out and start over because you didn't apply for the proper permit and have it inspected prior to the work being completed. This past year I buried a 240-v. line in PVC running out to my well pump house, and the local electrical inspector was quite a fuss-button in terms of what he required. He did a total of 3 inspections, and the first one (measuring the open trench depth) was the only one he didn't have some complaints about.
 
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Old 03-23-14, 11:15 AM
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Running 240v 50a wire in conduit inside a retaining wall

Some larger RVs take 240v@50a, and I've done this in a different part of the front yard. This is where I got the left over 1 1/4" conduit which happens to be the right length:
Photo Display Page

My purpose is to handle another RV of any size, and get a dongle wire to adapt the 240v outlet for a future welder.

As for how do I connect it, the pipe has to turn 90° to enter the RV box, and I'm not sure I have the room inside the blocks. A flexable waterproof pipe is probably the answer, if that's OK with code. Concreting the inside of the block wall will be done, (there's already rebar in there), not sure if I should cover these conduit pipes. Advice on that one would help.

Here's the wall, so far, and the RV outlet box will be on the rough side near the end (closest to the camera):
Photo Display Page

...and for the whole project:
Sagerquist Photography

Thank you for your help!!
 
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Old 03-23-14, 11:15 AM
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RV Curcuit

Larry, RV's with 2 air conditioners require 50 amp service.
 
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Old 03-23-14, 12:45 PM
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A flexable waterproof pipe is probably the answer, if that's OK with code
It is if it is listed for direct burial. However that tight of bend will be almost imposable to pull the wires through.

My suggestion would be to run the electrical conduit behind the retaining wall, then a 90 degree bend and come out the wall into the back of the RV box. Finally surface mount the RV box. This way you will only have a fairly small hole to make in the wall for the conduit.
 
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Old 03-23-14, 04:14 PM
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Nice-looking wall. I think I'd run the conduit in the wall, buried in concrete. A few horizontal rebar wouldn't hurt, either, tying everything together. The 90-degree bend can be made using an elongated, capped elbow--I'm pretty sure I've seen them made from PVC.

When are you going to bury the propane tank? Doing so will prevent your place from getting "black-coned" (meaning fire-fighters won't try to save the house, because of the danger of the propane tank exploding) should a wildfire come through. Also, I didn't see a firewood shed--just an Irish Setter shed.
 
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Old 03-24-14, 08:58 AM
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Ha! Athena approves all my projects as they progress. Those elongated, capped elbows aren't cheap, but in the space I've got, might be my best answer. Thank you!

I intend to move that propane tank, never thought of the "black-coned" concept. It currently sits where I'd like to build a storage shed. Maybe underground is my best option.
 
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Old 03-24-14, 04:18 PM
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You cannot bury a "capped elbow". (LB) Anything with a cover is required to be accessible. In the wall or buried in the ground is not considered accessible.
 
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Old 03-24-14, 05:02 PM
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I was wondering what a capped elbow was. The OP would have hated trying to pull through that.
 
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Old 03-24-14, 11:23 PM
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Thank you, Tolyn. I thought so.
 
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Old 03-24-14, 11:53 PM
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I think it depends on the circumstances. If a continuous, enclosed electrical wire or series of wires passes through a conduit fixture having a removable cap (meaning there are no possible connection problems that could result in the necessity of having to gain access to the fixture), why is this a problem? It's not nearly close to the same as having wire nuts making connections inside of a fixture, when connecting two or more separate wiring runs. I had an installation of continuous, 12-ga. insulated 3-wire inspected and approved by a city inspector in NM a few years ago, when I "buried" a capped elbow in a masonry mailbox enclosure I was building. Filled the open cavity with solid concrete after the inspection. If I remember correctly, the inspector's thinking was there is nothing here that needs access, as it's no different than using a curved sweep to make the bend and connection--just a means of enabling a continuous run of wiring to be made through an abrupt corner.

I must have done something right, as a few months after its construction, the mailbox survived a direct hit by a yuppie driving his BMW way too fast on the snow-covered street one day, when I happened to be shoveling snow off the nearby driveway. The front of the BMW was totaled, while the mailbox stood its ground proudly, with the embedded lights for the house's street number still working as intended.

Probably depends more on exactly what the local AHJ would approve. Assuming the OP is having this done under code and permit inspections.
 
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Old 03-25-14, 07:26 AM
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It's still a code violation (NEC) regardless of whether your installation was passed or not. In most cases, replacement wiring cannot be pulled past a closed LB condulet. I've seen many code violations overlooked in smaller more rural communities because many times the inspectors just don't know all the codes.
 
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Old 03-25-14, 08:16 AM
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Having a population of close to 300,000 people at the time, Albuquerque probably didn't/doesn't fit into "a smaller, rural community" category.
 
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Old 03-25-14, 05:14 PM
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But inspectors that don't know the codes can fit into any category.
 
 

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