Drilling outdoor vertical wireways and draining

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Tainted

Tainted

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Location
New York
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Engineer (PE)
I am specifying a 130ft vertical outdoor NEMA 4X wireway for a residential building. The wireway will be used to feed apartments every floor. Electricians will have to drill holes on the sides of the vertical wireway to install conduits as needed.

If you drill holes in the NEMA 4X wireway to install conduit, would that compromise the integrity outdoor wireway? What means and methods are used to make sure water does not get into the wireway when it is drilled? do you have to install some kind of gasket around the holes before installing the conduit?

Also would it make sense to put holes underneath the wireway to drain water incase water goes inside and drip to the bottom?
 
Post a pic of what you are thinking-
However, its overkill. When you use 4x you have to use meyers and rt conns... $$ (edit- here in phx at least)
Use r's...
 
rambojoe said:
Post a pic of what you are thinking-
However, its overkill. When you use 4x you have to use meyers and rt conns... $$ (edit- here in phx at least)
Use r's...
Click to expand...
There's no pic, it's a custom wireway from a local manufacturer. My design preference is 4X, don't want to go with 3R.
 
In my area, Seattle, 4X will trap moisture inside, and will need drainage holes. Instead of Meyers hubs can use sealing locknuts
 
Water is going to get in. It's almost impossible to stop. Even if it's just from condensation. You'll need some means for it to get out
 
tom baker said:
In my area, Seattle, 4X will trap moisture inside, and will need drainage holes. Instead of Meyers hubs can use sealing locknuts
Click to expand...
hmmm... the wireway will run about 25ft horizontally, every how many feet should you put a bottom hole on the wireway?
 
rambojoe said:
Post a pic of what you are thinking-
However, its overkill. When you use 4x you have to use meyers and rt conns... $$ (edit- here in phx at least)
Use r's...
Click to expand...
Most Type 3R wire way is designed for horizontal mounting. You only need Meyers hubs if you want to maintain the 4X rating.
 
jim dungar said:
Most Type 3R wire way is designed for horizontal mounting. You only need Meyers hubs if you want to maintain the 4X rating.
Click to expand...
Truth. They are strict here on roof stuff...you cannot just seal it or modify it nor drill. Dont ask.
To be clear, they really scrutinize solar regardless if you are ind/comm well known electric...i understand theses are feeders/branch which brings up fill questions... i dont know, nothing wrong with sillyconing the top of a r box. No tabs to deal with either.
In other words, some ahj say " well you are using ,thus must maintain rating..." unless indoors and industrial...
 
rambojoe said:
Truth. They are strict here on roof stuff...you cannot just seal it or modify it nor drill. Dont ask.
To be clear, they really scrutinize solar regardless if you are ind/comm well known electric...i understand theses are feeders/branch which brings up fill questions... i dont know, nothing wrong with sillyconing the top of a r box. No tabs to deal with either.
In other words, some ahj say " well you are using ,thus must maintain rating..." unless indoors and industrial...
Click to expand...
It is wrong unless it is an approved method and my guess would be it is not.
 
Tainted said:
I am specifying a 130ft vertical outdoor NEMA 4X wireway for a residential building. The wireway will be used to feed apartments every floor. Electricians will have to drill holes on the sides of the vertical wireway to install conduits as needed.

If you drill holes in the NEMA 4X wireway to install conduit, would that compromise the integrity outdoor wireway? What means and methods are used to make sure water does not get into the wireway when it is drilled? do you have to install some kind of gasket around the holes before installing the conduit?

Also would it make sense to put holes underneath the wireway to drain water incase water goes inside and drip to the bottom?
Click to expand...
I don't see any reason for a 4x. Water getting in thru the wireway isn't what happens, it comes in thru the conduits and/or their entries. Even with a 3r, more water will likely enter thru conduits than the wireway itself. What type of conduit will be used? FYI EMT rain tight connectors don't actually work, they leak all the time on runs I've installed and I'm pretty careful.
 
electrofelon said:
I don't see any reason for a 4x. Water getting in thru the wireway isn't what happens, it comes in thru the conduits and/or their entries. Even with a 3r, more water will likely enter thru conduits than the wireway itself. What type of conduit will be used? FYI EMT rain tight connectors don't actually work, they leak all the time on runs I've installed and I'm pretty careful.
Click to expand...
Rigid galvanized steel will be used. In NYC, it's against code to use EMT outdoors.

Anyway, if water will go through the raceways how can we stop it completely?

Would making holes on the bottom for drainage let more moisture in?
 
Tainted said:
Anyway, if water will go through the raceways how can we stop it completely?
Click to expand...
I've really never seen anything work. Part of the problem is they breath with thermal cycles. I2R heating warms the inside air and it expands, then rain or snow hits the outside of it, cools the air, and creates a vacuum pulling water in. The tighter you seal it, the greater the vacuum. Over a year all those little bits of water add up.
 
Tainted said:
Rigid galvanized steel will be used. In NYC, it's against code to use EMT outdoors.

Anyway, if water will go through the raceways how can we stop it completely?

Would making holes on the bottom for drainage let more moisture in?
Click to expand...
You will be using "W" rated conductors so water really won't matter and since you will have to arrange it to drain per 225.22 there has to be an openning somewhere.
 
Tainted said:
There's no pic, it's a custom wireway from a local manufacturer. My design preference is 4X, don't want to go with 3R.
Click to expand...
If there is no photo available, draw a sketch that captures the essence of your situation. It's a lot easier for others to understand what you have in mind, when a picture can speak for you instead of just words.
 
Tainted said:
Rigid galvanized steel will be used. In NYC, it's against code to use EMT outdoors.

Anyway, if water will go through the raceways how can we stop it completely?

Would making holes on the bottom for drainage let more moisture in?
Click to expand...
I think there is a good chance it will stay dry if you seal the conduit where it enters the building (the inside of the conduit, so air won't cool and condense as it convects to a lower temperature area), and use a sealant on the threaded joints. However I've never heard of anybody using thread sealant on RGS and I agree with the others to just not worry about it. Just make sure the conduits are arranged to drain and you provide some weep holes in any boxes or enclosures.
 
Laying out the pipe runs stratigically helps keep moisture at bay... but i dont think he liked any of the advice...
 
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