Duct Seal

[gbudke]

I am trying to find out some information to settle a debate between a co-worker and myself.
The job in question consisted of an underground service entrance with 5 parallel conduits feeding a 1600 amp 480/277 MSB. Where the conduits entered the building I set a 4' x 4' x 24" J box and filled the ends of the conduits with duct seal. I am from the north and recently moved to the area I now work/live in, and this is how it was always done. I am told that is not the case and is wrong can someone help me with this.
Thanks

 

[benaround]

What is their side of the story, how do they feel it should be done. Duct seal is ok in my book.

 

[Pierre C Belarge]

See 230.8 for sealing service underground raceways

 

[chris kennedy]

Also see 300.5(G).

 

[infinity]

See 230.8 for sealing service underground raceways

What about sealing overhead raceways?

 

[Volta]

What about sealing overhead raceways?

You mean 300.7?

 

[gbudke]

they say no box, no duct seal

 

[Pierre C Belarge]

they say no box, no duct seal

Did you read the section number(s) provided?

 

[Pierre C Belarge]

What about sealing overhead raceways?

Overhead supplied from where?


230.8 - underground
300.5(G) - underground or overhead...depends on how the water may be entering the equipment.
300.7 - underground or overhead...depends on how the water may be entering the equipment.

 

[glene77is]

they say no box, no duct seal

300.7
"Raceways Exposed to Different Temperatures"
is what I read.
"Shall be filled" with a sealing material.

 

[hardworkingstiff]

I've never had an inspector call this out on underground conduits entering troughs or panels. I just recently started doing it.

 

[benaround]

they say no box, no duct seal

I don't see where a box is required, but, the raceways must be sealed. So, I guess you

are both batting .500 .

 

[chris kennedy]

I've never had an inspector call this out on underground conduits entering troughs or panels.

Miami-Dade country required duct seal for years when I worked there. I work in Broward county now and it's not enforced.

Edit to add: IMO duct seal is not much more than window dressing.

 

[infinity]

300.7
"Raceways Exposed to Different Temperatures"
is what I read.
"Shall be filled" with a sealing material.

That was the one I was thinking of. :grin:

 

[chris kennedy]

What about sealing overhead raceways?

300.7
"Raceways Exposed to Different Temperatures"
is what I read.
"Shall be filled" with a sealing material.

How would a riser for a service drop meet these conditions?

300.7 Raceways Exposed to Different Temperatures.
(A) Sealing. Where portions of a cable raceway or sleeve are known to be subjected to different temperatures and where condensation is known to be a problem, as in cold storage areas of buildings or where passing from the interior to the exterior of a building, the raceway or sleeve shall be filled with an approved material to prevent the circulation of warm air to a colder section of the raceway or sleeve. An explosionproof seal shall not be required for this purpose.

 

[iaov]

I've never been a fan of duct seal and have questions as to wether or not this would be a material that is listed for sealing electrical raceways.

 

[cadpoint]

What about Hilti or 3M paste ? Or any of the other compariable stuff like it?

 

[benaround]

I've never been a fan of duct seal and have questions as to wether or not this would be a material that is listed for sealing electrical raceways.

Well it is called, Duct Seal !!

 

[Pierre C Belarge]

The purpose of the "seal" is to stop the flow of warm air to cold air, creating condensation & moisture. It is not intended to stop the flow of water per se.

 

[ptonsparky]

Duct seal works if you take the time to instal it correctly.