open-ended conduit through penetration 2-hour fire wall

[twd22285]

I have a project where 1" and 3/4" conduit is penetrating a 2 hour fire wall. the annular space around the conduit is sealed with FS-ONE MAX. On one side of the fire wall, the electrical system is closed. on the other side, the conduit is open at 12" and cabling and wire will go to a cable tray. In order to maintain the 2 hour fire rating, what is standard practice for sealing the open conduit?


Tony
NICET 2 Fire Sprink Design
ICC Fire Inspector 2

 

[cranky108]

Fire stop foam. It is an expandable foam that is sprayed into the conduit.
We typically don't use it as we use a rodent stop foam, because it is a bigger issue, and we have a different application.

 

[TugboatEng]

The modern systems use some type of intumescent foam or caulk. Follow manufacturers recommendations though I know some are making erroneous claims about their products. I believe you need to space each cable apart so the foam or caulk has some thickness between each strand. I usually see mineral wool packed around the cables to create this spacing.