mvaldes1989
Member
- Location
- 1595 ne 135st north miami 33161 fl
why cant I install a new panel in a firewall but j-boxes are ok ?
1. Are you sure they are? Even if mounted back to back?why cant I install a new panel in a firewall but j-boxes are ok ?
RogerFrom the UL Fire Resistance Directory
WALL AND PARTITION ASSEMBLIES
Metallic Eletrical Outlet Boxes
Listed single and double gang metallic outlet and switch boxes with metallic or nonmetalliccover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2h. These walls shall have gypsum wallboard facings similar to those shown in Design Nos. U301,U411, and U425. The metallic outlet or switch boxes shall be securely fastened to the studs and the opening in the wallboard facing shall be cut so that the clearance between the box and the wallboard does not exceed 1/8 in. The surface area of individual metallic outlet or switch boxes shall not exceed 16 sq in. The aggregate surface area of the boxes shall not exceed 100 sq in per 100 sq ft of wall surface.
Metallic boxes located on opposite sides of walls or partitions shall be seperated by a minimum horizontal distance of 24in. This minimum seperation distance between metallic boxes may be reduced when "Wall Opening Protective Materials" (CLIV) are installed according to the requirements of their Classification.
again my question would be can I replace an existing panel for a new one if tis located in a fire wall ?
again my question would be can I replace an existing panel for a new one if tis located in a fire wall ?
I second that but, from the way the OP is asking the question it sounds like the AHJ has already made the ruling.Only your ahj can tell you that.
I'm going with this answer too.Off of the top of my head, I believe that for a box in firewall the penetrations are limited to 16 square inches.
The thing about wrapping it is that you wont find a "listed" or "approved" method. Always best to check with the AHJ and see what they allow.If the penetration of the box is greater than 16" you must firerate around it -- putty pads, 5/8 X sheetrock - check with the building dept & proposed a solution -- there are 3 basic rules for electrical boxes - penetration lgreater than 16" -- through penetration (boxes facing opposite directions) with in 2' horizontally -- 100 sq in of combined penetrations (IE: 13 - 1gang openings)within 100 sq ft of wall
I have done this (Wrap it with 3M fire pads) many times and has passed inspection without any problem. View attachment 9359
But check with your AHJ first.
I have done this (Wrap it with 3M fire pads) many times and has passed inspection without any problem. View attachment 9359
But check with your AHJ first.
The OSB was the wall of the garage that was getting finished with 5/8" sheetrock.
Instruction that come with the fire pads.
http://multimedia.3m.com/mws/mediaw...sPad_PDS_4620-4.pdf&fn=FB Moldable Putty+.pdf
Read sections #2 "Applications" and #6 "Installation Techniques" and note the sizes of boxes they can be used on.
Wrapping a load center with them is beyond their limits.
Roger
For larger applications, pads can be molded together by hand. section 2 -- pretty strong statement --