Condensation

[kda3310]

We have condensation dripping down from three parallel runs of 500 kcmil on to a 1200 amp breaker. The room is air conditioned and the conduits runs to the outside in the sun. I know there is some sort of blocking I am supposed to put into the conduit but, I have never done this. Does the blocking have to be exactly where the inside meets the outside? I don't think i can get to that exact point. Can it be a little before or a little after? What do I use for the blocking and how do I apply it? Does it have to be completely sealed all around the wires? Any info would help.

 

[infinity]

We use duct seal pressed around the condcutors and into the conduit. The idea is to keep the air from moving through the raceway it does not need to be waterproof .

 

[GoldDigger]

There are a variety of products that would keep moist air from infiltrating into the conduit and condensing where it meets the cooler environment.
My main concern would be to block the space as close to the outside as possible and also locate it such that moisture condensing anywhere on the outside of the block will be able to drain instead of pooling at the block.
For this reason, for example, blocking right at the bottom of a vertical run into the panel would be a bad idea.
The other alternative is simply to provide drainage for the condensation where it will not cause any damage and leave it at that.

 

[FionaZuppa]

condensation, on the outside of the conduit? i dont think ductseal will help with that. what's the humidity level inside the room?

or do you mean 3 vertical runs that land in panel and water is dripping out of them inside the panel? definitely block where conduit transistions from hot to cold, etc.

perhaps you need a room dryer, or, perhaps inside should have been sched-80 pvc ?? metals will condense water sooner than non-metals.

 

[rlundsrud]

As stated previously, duct seal at the point where the conduit enters the building. You have warm moist air entering the conduit and condensating inside the building due to the conduit being cooled from the cooler inside ambient temp. Duct seal is a putty that you pack around the cables to seal the conduit.

 

[sameguy]

As stated previously, duct seal at the point where the conduit enters the building. You have warm moist air entering the conduit and condensating inside the building due to the conduit being cooled from the cooler inside ambient temp. Duct seal is a putty that you pack around the cables to seal the conduit.

Duct seal can also be used to cover the hole you drilled from the basement to out doors, you could see the neighbors maple tree, and painted over when the painters went to lunch; or so I hear.

 

[just the cowboy]

They also make a special spray foam

They also make a special spray foam

They also make a special spray foam for this that won't damage the wires.

Cowboy

 

[tom baker]

If the condensation is inside the conduit, duct seal will work but Polywater FST will do a better job. You need to stop moist air getting inside the conduit and condensing.
There is some code language that requires sealing, the product must be identified, that means spray foam can't be used.

 

[just the cowboy]

If the condensation is inside the conduit, duct seal will work but Polywater FST will do a better job. You need to stop moist air getting inside the conduit and condensing.
There is some code language that requires sealing, the product must be identified, that means spray foam can't be used.

I think it is Ideal that makes one for electric pipes and wire.