Water Stop for Conduit

[mayanees]

What is a good water-stop/conduit fill material to prevent moisture/condensation/fluid from running through conduits?

The pipes I need to seal contain 480V, (3) 500kCM CU cables per pipe.

Thanks for any responses.


JM

 

[donselectric]

good luck.....:wink:

 

[electricalperson]

will this work?

 

[electricalperson]

or using seal off fittings where you enter and leave a different tempature area

 

[chevyx92]

How about duct seal?

 

[donselectric]

thats why its a wet location... no matter what you do you'll
never stop water from accumulating in a underground piping system.
you may slow it down from above ground entering by seal offs but thats
about all...

like i said good luck and whatever you use make sure its listed
don t just buy a tube of whatever and start filling the conduits with it
you'll be sorry.....

 

[Dennis Alwon]

thats why its a wet location... no matter what you do you'll
never stop water from accumulating in a underground piping system.
you may slow it down from above ground entering by seal offs but thats
about all...

like i said good luck and whatever you use make sure its listed
don t just buy a tube of whatever and start filling the conduits with it
you'll be sorry.....

The Op never said it was an underground installation. It could be in a building where the conduit passes thru a very cold area into a conditioned space. Condensation collects in the pipe. We had a thread on the before-- I'll see if I can find it.

 

[Dennis Alwon]

Here is the link

 

[electricalperson]

aranging the conduits so they dont drip on the top of the panel is also a good idea. like putting an LL or LB on the side of the panel or box instead of on top

 

[tryinghard]

I don't think there's any such thing as a dry underground conduit, use cabel that is rated for wet location and or THWN (suffix 2 allows 90 degree rating, see Table 310.13).

EYS seals are probably the most efficiant, until you need to install another conductor Duct seal is what we've always used.

 

[ultramegabob]

refridgeration techs use a product they call thumbgum when sealing penetrations on coolers to prevent condensation. I think the one of the brand names is Presstite Permagum.

 

[220/221]

If you stop the water, how will you be able to achieve the proper conduit fill?:wink:



In some cases (car wash?) it would be advisable just to accept it and give it an escape route.

 

[RUWired]

There are air bags that can be inflated to go around these wires, but i can't remember the name of them. I've also used a foam expander for water and it held up.

 

[acrwc10]

What is a good water-stop/conduit fill material to prevent moisture/condensation/fluid from running through conduits?

The pipes I need to seal contain 480V, (3) 500kCM CU cables per pipe.

Thanks for any responses.


JM

Can you give us some more detail to how this is run , under ground, across a roof, threw a septic tank, etc.?
For under ground conduit coming up in to a panel or building , Duct seal. If a pipe is running under ground down hill , concrete pull box with drain rock at the bottom of the hill.

 

[tryinghard]

In some cases (car wash?) it would be advisable just to accept it and give it an escape route.

We have circuitry in tunnels, wet & cold environment, and this is just the case. These use to be GRC but rusted and evolved to PVC with PVC outlet boxes for lighting. PVC tee's can be used to simply let the water out, without these condensation builds throughout the long runs (some 400'), it then collects and fills the sealed light outlets and fixtures.

 

[acrwc10]

We have circuitry in tunnels, wet & cold environment, and this is just the case. These use to be GRC but rusted and evolved to PVC with PVC outlet boxes for lighting. PVC tee's can be used to simply let the water out, without these condensation builds throughout the long runs (some 400'), it then collects and fills the sealed light outlets and fixtures.

The ones that I have seen like yours they run the conduit lower then the light fixture then use a conduit body to tee off (upward) to the fixture. this gives a low point in the jbox before the light. Not the best solution but better then a light full of water.
What about explosion proof fittings? I don't know if that would work for water, just throwing it out there.

 

[tryinghard]

I really think condensation is the greatest contributor, although leaks can develop over time. In tunnels long runs may start in a dry environment of 60 degrees and end in a wet or running water environment at 30 degrees. This must affect the air inside the conduit.

 

[mayanees]

TX for the responses

TX for the responses

Can you give us some more detail to how this is run , under ground, across a roof, threw a septic tank, etc.?
For under ground conduit coming up in to a panel or building , Duct seal. If a pipe is running under ground down hill , concrete pull box with drain rock at the bottom of the hill.

This is an installation where two (2) 480V, 4000 amp concrete ductbank feeders are brought in from separate 3000 kVA transformers to separate 480V, 4000A switchgear which is located in a building next to the xfmrs.

I haven't actually seen the installation yet, or at least paid attention to the pipe elevations, but I'm afraid the outside pipes are at an elevation that backs up the conduit with water after a heavy rain. There's containment for the liquid-filled padmounts that fills up after heavy rains, and is slow to drain down. It's the flow-through membrane type that plugs if it senses oil, but slowly lets water pass.
When the contaiment is full, the water covers the pipes - but is still several feet from the transformer terminals.

I think the real issue is that a roof scupper drains into this area - where there are (2) 3000 kVA xfmrs, and (2) 2 MW gensets, flooding the area for the duration of a big storm.
I don't think the electrical system is designed to be subjected to water levels that result in water percolation into the building.

But as a first line of defense, we need to stop the flow.
I will likely recommed "sealing with an approved, listed material".
But if anyone can suggest a product I'd appreciate it.

Thanks

JM

 

[mayanees]

Raychem RDSS

Raychem RDSS

One of the guys in our office just recommended something that looks like the appropriate sealer - Raychem Dust Sealing System (RDSS) for Power Cables.

They're inflatable adhesive sealant bladders specifically designed to, among other things, prevent flooding in cable vaults, filled by using CO2 charges or by pneumatic means.

So that's what I'm recommending, with a qualifier that the flooding/drainage issue be resolved as the first line of defense.

JM

 

[stickboy1375]

What is a good water-stop/conduit fill material to prevent moisture/condensation/fluid from running through conduits?

The pipes I need to seal contain 480V, (3) 500kCM CU cables per pipe.

Thanks for any responses.


JM

http://www.polywater.com/ductseal.html