electrical subfed panel in a firewall commercial

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elect78

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I didnt have any problems but it raised some questions i have a subfed panel that had to be put in a firewall that was gonna have fire rock on both sides i ran all my home runs in bx cable and all went down one side so the fire marshall said that the firewall was useless on that side so instead they doubled the other side instead just outa curiosity is there a better way that i could have done that or is it just what it is and there was nothing else i could do any oppinions would help in the future
 
Firewalls have opening & membrane penetration restrictions. This is typically a local or state building code issue. In addition, if it is a UL listed wall design, it also has specific restrictions. Need to check with the local building/electrical official. Best to keep openings/penetrations in a firewall to a minimum.
 
Due to the fact that the panel opening is more than 16 sq inches and is usually more than 100 sq inces, you would never be allowed to put a panel in a rated wall. Many jurisdictions will allow you to put a 2x4 with drywall on it at the top and bottom of the panel, but as you did, you still need two layers of drywall on the back.

You will not find a listed assembly that shows a panel in a rated wall. The best bet is to make an alcove or a closet and suface mount them.

By the way the information about this comes out of the building code.
 
cowboyjwc said:
Due to the fact that the panel opening is more than 16 sq inches and is usually more than 100 sq inces, you would never be allowed to put a panel in a rated wall. Many jurisdictions will allow you to put a 2x4 with drywall on it at the top and bottom of the panel, but as you did, you still need two layers of drywall on the back.

You will not find a listed assembly that shows a panel in a rated wall. The best bet is to make an alcove or a closet and suface mount them.

By the way the information about this comes out of the building code.
Click to expand...

I agree, the best way to do this is to surface mount the panel on the firerated wall and box around it.

Chris
 
Is it a true "Firewall" or is it a "Fire Partition"?

I doubt you would be allowed to breach any "Firewall" as they are mostly concrete and extend above the roofline and outside the exterior walls.

Firewalls are self supporting and allow one side of a structure to collapse without knocking down the firewall.

Attaching anything to firewalls usually means attaching with plastic anchors that melt and all pass through equipment is below 3' above the floor.
 
Also note that not only are panels not allowed in a rated wall, you can't put a three gang or larger box or a cut in box in one.

No opening larger than 16 sq inches and no more than 100 sq inces of openings in 100 sq feet. Boxes must be secured to the structure.

And actually a fire wall and a fire partition are treated the same for the electrical.
 
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I would agree w/ cowboy...A rated wall is a "system." Thank about it - what good is doubling up on one side if a fire was to break out on the "panel side" of the rated wall, what good does applying a double layer of Sheetrock do if what is supporting it crumbles to the floor?
 
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