# seal conduit btwn atmoshperes



## Bbsound (Dec 16, 2011)

It cant hurt.


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## wendon (Sep 27, 2010)

Why don't you just seal them off on the other end? Or seal them where they enter your panels etc. If they're actually running above the insulation in the unheated space, I'd probably consider just sealing them with silicone to make sure you don't have any air movement.


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## Wirenuting (Sep 12, 2010)

buddhakii said:


> I have conduits coming from an attic dropping into the top of an mcc and a few control panels in the electrical room. Told the boss today that I'm installing condulet's coming out of the attic so there is a point to seal the conduits to prevent condensation. He said he never heard of that and it's not in the bid. Attic=hot, electrical room=cold. What am I missing here? The last thing I want is condensation dripping onto expensive electronic equipment.


I see it all the time, but it's the cold attic with heat rising up they the conduit.. Use some Perma-gum, duct seal.. A small plug goes a long way.. I use it for any attic penetrations now and for service entrances.


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## raider1 (Jan 22, 2007)

Show your boss 300.7(A).



> 300.7 Raceways Exposed to Different Temperatures.
> (A) Sealing. Where portions of a raceway or sleeve are
> known to be subjected to different temperatures, and where
> condensation is known to be a problem, as in cold storage
> ...


Chris


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## sbrn33 (Mar 15, 2007)

You should not need a conduit body for that. Just seal the ends of the conduit with duct seal. Quit spending the boss's money. He needs that!


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## Jlarson (Jun 28, 2009)

Can of foam, done.


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## BBQ (Nov 16, 2010)

Jlarson said:


> Can of foam, done.


Not saying I have not done so but the foam people will not say it is ok for the insulation.

For those that get inspections this could be a costly fix.


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## Jlarson (Jun 28, 2009)

BBQ said:


> Not saying I have not done so but the foam people will not say it is ok for the insulation.
> 
> For those that get inspections this could be a costly fix.


Use the polywater foam if you're dealing with a :jester: of an inspector.


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## BBQ (Nov 16, 2010)

Jlarson said:


> Use the polywater foam if you're dealing with a :jester: of an inspector.


I would use duct seal, it is what it is made for.


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## Jlarson (Jun 28, 2009)

Duct seal is like split bolts. :yes: :laughing:


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## BBQ (Nov 16, 2010)

Jlarson said:


> Duct seal is like split bolts. :yes: :laughing:


:laughing:


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## Jlarson (Jun 28, 2009)

See, you know I speak truth.


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## BBQ (Nov 16, 2010)

Jlarson said:


> See, you know I speak truth.


I would still use duct seal, it does the job the OP is talking about. It is safe for the conductors, it removes easily. It is also inexpensive.


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## buddhakii (Jan 13, 2011)

The inspectors around here accept dap expanding foam door sealant. And I guess I just allways thought it had to be sealed at or close to the point of the penetration. I will not be going with the condulets. Thanks guys.


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## Southeast Power (Jan 18, 2009)

buddhakii said:


> I have conduits coming from an attic dropping into the top of an mcc and a few control panels in the electrical room. Told the boss today that I'm installing condulet's coming out of the attic so there is a point to seal the conduits to prevent condensation. He said he never heard of that and it's not in the bid. Attic=hot, electrical room=cold. What am I missing here? The last thing I want is condensation dripping onto expensive electronic equipment.


I think now that weed is legal out there, we will be seeing more of this kind of thing.


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