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For a clean look, I want to run EMT directly into the back knockout of a disconnect box and am wondering if my methodology is correct or if this violates code.

My wiring is in the basement and the disconnect will go to the other side of the wall. I'm running 1/2" EMT through the cinder block and stucco exterior. I then plan on using a wet rated EMT compression fitting on the conduit to connect to the disconnect box.

My main concern is there is a small space between the disconnect box and the wall due to the disconnect box having 4 touch points to the wall. The only thing that is exposed to the elements would be the wet rated fitting. So I think I'm okay.

Here's what I'm thinking...

Crude drawing

I couldn't find a different fitting that could be entirely installed from inside the disconnect and still leave me enough room to manage the 6/2 wire that's coming in.

Paul Evans
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    Novice question from a non-electrician or handyman: When you say "approved" or "compliant", is it assumed that you're talking about the electrical code for a specific country, such as the U.S.? I would have guessed that different countries/states/provinces have different electrical codes. (For what it's worth, I'm Canadian.) – User1974 Jul 01 '22 at 08:06
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    @User1974 in the context of most/all electrical questions on this site, "approved" and "compliant" usually refer to the electrical code (NEC = National Electrical Code, in the United States. I think Canada's is different, but I'm not Canadian). Not to be confused with "listed", referring to UL Listed. (UL = Underwriters Laboratories). With electrical installations, you are only permitted (by NEC and often by your insurance as well) to install equipment/devices which have passed thorough testing by UL. – maples Jul 01 '22 at 13:38

1 Answers1

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It is code compliant to run the rain tight from the box through the wall. When I do this my concern is water ingress from the hole in the wall.

I usually will create a chevron or inverted v of caulk above the hole and then on the top and sides of the box leaving the bottom open (at least partially open) this way if the top leaks the water runs down the wall around the hole and out the bottom.

In my early years I used to seal all 4 sides until finding boxes holding water up to the hole and rotted wood and even wall damage although those had been in for decades to cause that damage it was suggested to leave the bottom open at least in part to allow drainage if the caulk failed at the top.

Sealing through the block can be done but I trust diverting around the hole after many years it works.

Ed Beal
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  • It is code compliant to run EMT using compression fittings. Liquid tight is just to make life easy. You're supposed to drill holes in masonry with a slight pitch to outside. – Mazura Jun 30 '22 at 20:43
  • Liquid tight is way more expensive also and not needed imo – Ed Beal Jun 30 '22 at 22:07
  • It's a little confusing with rain tight. When did they even start making the ones with the plastic bushings? And added code for them? I can't use it outside if it doesn't have the bushing? I should see what it says on the box? – Mazura Jun 30 '22 at 22:19
  • Mazura they started adding a color to rain tight years ago light blue and green there are some that have a metal ring that interlocks when tight providing the seal and the electrical connection but they can be a PITA with a plastic /nylon seal or the metal one. – Ed Beal Jun 30 '22 at 22:41