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Discussion Starter · #1 ·
I have 1/2" EMT attached to the side of a house which comes down the wall into a weatherproof box with a receptacle. A 3/4" RNMC comes up from the ground next to the house, up the wall and into the same box using a male terminal adapter. The problem is whoever installed this didn't do it right. The weatherproox box has 3/4" hubs. The 1/2" EMT has a connecter on it inserted into the box. Just inserted. Not threaded in because it isn't the right size. What should I do to correct this? I was looking at a rigid reducing bushing which will work with an EMT fitting, but apparently they are only for use in dry locations. Should I cut the terminal adapter off the RNMC and glue on a reducer? I was looking at various reducing fittings in the Carlon catalog but I'm not quite sure I understand how they work. If I need multiple pieces, etc.

Also, I want to make sure I am correcting some other portions of this the right way. The original installation was done with die-cast EMT set screw couplings and box fittings. I've replaced all of those with raintight fittings. How does one make RNMC entering a weatherproof box raintight? Do I glue it in or use some sort of thread sealant or anything?

Hope this makes sense, otherwise I can draw a sketch.

Thanks
 

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How far is the emt extending from the wall? Can you get a picture of it?

Is it possible to notch around the emt and install the proper connectors to install a box flush on the wall?
 

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Discussion Starter · #3 ·
How far is the emt extending from the wall? Can you get a picture of it?

Is it possible to notch around the emt and install the proper connectors to install a box flush on the wall?
Not sure I understand what you are suggesting. Can't take a photo right now but here is a sketch...

 

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Use a reducing fitting for galvanized plumbing pipe. No, it isn't UL listed for that particular purpose, but it is surely capable of standing up to a wet environment.

As to sealing a weatherproof box, you pipe is coming from the bottom, so there really isn't a need to seal the treads. Otherwise, the connection between the threads is still pretty tight. I have never had a problem with water entering a box in that manner.
 

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Discussion Starter · #5 ·
Use a reducing fitting for galvanized plumbing pipe. No, it isn't UL listed for that particular purpose, but it is surely capable of standing up to a wet environment.
That's not a bad idea but there has to be a code-compliant solution without the use of a plumbing part. I thought the threads are slightly different on plumbing vs electrical fittings. I wonder if the rigid reducer bushing I was looking at in the hardware store has a different listing than the one I linked to. The one I saw was actually steel, not die-cast zinc.

I thought about using a weatherproof box extension ring with 1/2" hubs but I'd like to avoid that...
 

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An explosion-proof bushing would be watertight, but you'd have to go to an electrical wholesaler to get one. And they'd likely have to order it for you.

Rob
 

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This easy, though it requires a number of parts. First use a reducing bushing in the 3/4 hole.Then for the sealing part, use a sealing locknut ( a steel locknut with a built in gasket) on a threaded close nipple. Screw on a GRC coupling. Then to the female end of the rigid coupling, screw in a threaded PVC fitting.
 
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