NEC Code and penetration thru FireWalls

[cyberpunk84]

Gentleman,

I'm a designer for DoD - OCONUS Installation.

The project (under NAVFAC) is referred to the replacement of the existing system (a Blue Nurse call system) in the OCONUS USNH in Italy.
The new electrical distribution will be in EMT conduit (requested from USNH) thru the building (existing).

The design phase has been concluded without critical issue, and from 2 week is started the construction phase.

Yesterday, during an ispection on the site with QA (Quality Assurance from Government), we checked the installation of the EMT conduit thru a fire rated wall.

We provide in the design, we provide this installation detail for metal sleeves:



QA told me if is possible minimize the distance of 50mm between the EMT and the Sleeve Pipe.

I didin't find any prescriction from the NEC code about this "clearance" from the EMT and sleeve pipe.

Have you some indication or section of NEC about this?

Thank you for your help!

/r

 

[Dennis Alwon]

I believe this may be a fire code or building code issue not an NEC issue.

 

[mgookin]

50mm = 2 inches.

Inside of D is 1" from outside of d in your drawing (50mm/2). That space is packed with firewool.

You want to reduce the 1" space?

 

[cyberpunk84]

50mm = 2 inches.

Inside of D is 1" from outside of d in your drawing (50mm/2). That space is packed with firewool.

You want to reduce the 1" space?

I'm sorry for the use of metric standard :happysad:
50mm is equal to 1" around the EMT.
US Gov't provides this standard for OCONUS installation :angel:


Yes, QA would decrease the space filled with rock wool and would like to know if the Electrical Code (or other US laws applicable) have some indication about this installation. He wants an referenced indication.

I tried to find something on the Code, but I didn't found anything.
There's others section of other codes (i.e. IFC/NFPA/IBC) with this indication?

 

[cyberpunk84]

I believe this may be a fire code or building code issue not an NEC issue.

This is also my idea. But him continues to ask.

I found only the article 300.21 (baseline for the design)
"Article 300.21 Spread of Fire or Products of Combustion:
Openings around electrical penetrations through fire-resistant rated walls, partitions, floors or ceilings shall be fire stopped using approved methods to maintain the fire-resistance rating.?

 

[mgookin]

When someone wants to change a design I usually refer them to the person who did the design. I see from your profile that you are the designer. That being said, it's common to have a 3/8" annular space firecaulked in the situation you describe. I'd still put the wool in there and let it sit back so you can get a good bead of firecaulk around it. In this case maintain at least 3/8" so you get a good application.

FYI: 3/8" = .375 * 25.4 = 9.5mm (call it 10mm). So the ID on the pipe needs to be 20mm larger diameter than the OD of the emt.

 

[cowboyjwc]

You have to look at the manual for the specific fire stopping product used and it will tell you how it is to be installed. The problem is that many of the details you see on the plans are just "cut and paste" with no reference to an actual product.