How to enter the top of an exterior wireway

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jzadroga

Member
Location
MA
What is the best way to enter the top of a NEMA 3R wireway using PVC fittings?

I have an installation where the previous electrician just came in the top with PVC TA's and locknuts. Rain has been dripping into the wireway by following the PVC entry. I have looked but I cant find any better way using PVC. I know there must be something.
 

Fulthrotl

~Autocorrect is My Worst Enema.~
What is the best way to enter the top of a NEMA 3R wireway using PVC fittings?

I have an installation where the previous electrician just came in the top with PVC TA's and locknuts. Rain has been dripping into the wireway by following the PVC entry. I have looked but I cant find any better way using PVC. I know there must be something.

myers hub, close nipple, and FA.

it's the least likely to be sheared off from a side hit,
and listed waterproof.
 
Ditto on the Myers hub. Not sure if it applies to your situation or not but the NEC 2014 allows for a 1/4 weep hole to be drilled into conduit bodies and boxes. Definitely helps drain out condensate and/or any rain from a bad conduit seal.

Double check 314.15 to make sure it applies to you.
 

kwired

Electron manager
Location
NE Nebraska
Ditto on the Myers hub. Not sure if it applies to your situation or not but the NEC 2014 allows for a 1/4 weep hole to be drilled into conduit bodies and boxes. Definitely helps drain out condensate and/or any rain from a bad conduit seal.

Double check 314.15 to make sure it applies to you.
NEMA 3R wireway in the OP should already have arrangements for drainage.

Still is a good idea to use something that resists leakage around the fittings better then what standard male adapter with standard locknut does though. You still very well can get condensation entering the wire way that originated from the inside of the raceway though.
 

Carultch

Senior Member
Location
Massachusetts
What is the best way to enter the top of a NEMA 3R wireway using PVC fittings?

I have an installation where the previous electrician just came in the top with PVC TA's and locknuts. Rain has been dripping into the wireway by following the PVC entry. I have looked but I cant find any better way using PVC. I know there must be something.

Carlon makes a sealing gasket for this application. Albeit, limited to trade sizes 2" and less.
http://www.cesco.com/b2c/product/Carlon-E943JW-Neoprene-Flat-Sealing-Washer/334596

Using sealing locknuts and Myers hubs, may seem to work as a solution, but on paper they are only formally rated to be used with RMC. I don't see a real life consequence of using such a product with a PVC male adapter, since the threads are NPT on both products, and should get a proper waterproofing.
 

kwired

Electron manager
Location
NE Nebraska
I agree also. I have never seen MAs fail the way you have, but as just noted, myers hubs are only listed for RMC so I believe this to be fully code compliant.
Omit expansion fitting where you should have or secure it so tight it can't expand and you might see it fail that way. Installed in direct sunlight or at least on sunny side of a building seems to increase that chance as well.
 
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