Repair of Rigid Metal Conduit

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Re: Repair of Rigid Metal Conduit

pierre said:
Is there a product that can be used to "cold weld" damaged rigid?
Click to expand...

Not that I am aware of.
How would one keep the dimensions (primarily interior diameter) constant?

What is the situation?
 
A GC was using a jackhammer to open the concrete floor, adding a long run for a new drain. In the process he sawcut and jackhammered his way through a number of rigid metal conduits. They will need to be cut open to repair/ replace conductors (some circuit breakers tripped) and hopefully there is some type of repair kit (such as for PVC), so a box will not need to be installed. I believe this is a well used hallway in and around the kitchen.
 
I think the best you could hope for is threadless connectors in combination with unions.

Are the above listed for direct burial? I'm thinking no, based on old info. Maybe things have changed.

You could always have him tape it up real good.

And install an equipment ground for good measure. Unless the unions and threadless connectors ar listed for direct burial.

code compliant? most likely not. Will it be ok? Most likely yes.

It's a compromise I would accept.

Your or your AHJ's call.
 
This building was built in '78. The asbuilts are not great. Just locating the start and finish of some of these conduit runs may be a project in itself. Some of the damaged conduits are damaged in length long enough that it would require more than one box, or a long trough. The problem there is this is a hallway. What kind of cover (to support foot traffic) for these would be satisfactory?
 
How deep are these conduits? I am thinking about two accesable j-boxes in the floor to allow repairs/resplicing. Join the two together with pvc conduits and make sure to bond. As for the ability to get to the conduits for necessary cutting / unscrewing to allow repairs, inform jackhammer man he has more work to do.
 
They make "split duct" conduit. It has side flanges that allow it to be bolted together and the ID of the "split duct" matches the OD of the conduit to be repaired. I don't have a link to a source here at home, but I think that I do at work. I will check tomorrow.
Don
 
Wouldn't replacing the wire completely be preferable? A repair of the conduit would require only one stick and an Erickson coupling, and pull the damaged wires from each end.

Compared to the work involved with using boxes, aligning the access covers with the floor, and making multiple splices, it seems that a metallic repair and re-pull is in order.
 
I would repull all the runs.The repair part should be easy with threadless couplings (no violation that i know of).Bottom line is its yours after the repair and your not footing the bill.Do what ever it takes to make it good as new and cover your own a$$.And pull a ground wire while your at it.On way home stop and cash in that cut copper :D
 
Thanks for the replies.

Don, it would be great if you could find the link.

Remember this is a hallway that is approximately 4 feet wide, with the cut taking up to 2 1/2 - 3 ft.
I agree that the conductors may need to be repulled, as some of these are almost 30 years old.

As a note:
This building used to be the site of the Stouffer Hotel, which had a horrible fire years ago, killing many people. You would think that the history would have the management think twice, but money is the ultimate deciding factor here. The contractor had all he could with convincing them that he should make the repairs, and not the maintenance people.

Also when this occurred, the breakers were reset by maintenance, and all of them held.... :shock: . Of course they could not remember exactly which breakers had tripped :cry:

 
Posting the pictures kind of screwed up my post.

As you can see in the 3rd picture, the volt tic is showing the conductors are energized... nice... safety first!!!!

BTW: The floor was marked out, only the demo crew obviously did not care.
 
Pierre,
Here is the split conduit that I was thinking about. No matter what type of repair is used, you will have to make sure that there are not sharp edges inside of the existing conduit that would damage the wire. If there are holes punched in the conduit by a jack hammer bit, that part of the conduit should be cut out.
Don
 
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