How to handle service cable passing through firewall?

[StephenP]

There will be a 5/8" sheetrock 'firewall' between the living space and the garage in the addition I am working on. The main 200 amp service panel (outside) and the new 100 amp subpanel (in the garage) are on opposite sides of this firewall. I will be running the cables through the attic. What is the proper way to pass the cable through the firewall? My first thought was to use a junction box on the garage side, then come out through a hole in the box, with a clamp, then on to the subpanel. I appreciate any help. Thanks.

Stephen

[kadoka]

Stephen

I have my main box in the garage. I ran the wires up behind the drywall to the space above the drywalled ceiling and ran them to the house that way. They didn't actually have to breach the firewall that way. The firewall between the garage and the house does not go all the way to the rafters, just to the level of the ceiling in the garage which is also the fire rated drywall.

[Sparks]

From what I think you're asking there is no need for a junction box. If you need to penetrate the firewall just make sure it is sealed properly around the penetration. (drywall compound, caulk, fire-rated caulk). Some inspectors are content with plain compound, some demand fire-rated caulk. All your really need to do is maintain the protection of the firewall.

[StephenP]

Cool. That sounds simple enough. Thanks!


Stephen