New one for me on this one. Installing a panel in a commercial office building, 277/480. Mounted it on a double sheetrock fire wall. The electrical inspector is requiring that I first mount plywood to the wall and mount my panel to that. I’m not finding anything NEC to back it up, maybe it’s a local thing. Is there anything in the NEC that calls those out??
Plywood backer required?
- Thread starter BeeGee23
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rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
No. I'm sorry. Does your inspector want the plywood to be fire resistant as well? Just kidding.
Good luck!
Ron
Johnhall30
Senior Member
- Location
- New Orleans, LA
- Occupation
- Engineer
The inspector is living in a made up fairytale land
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Not required by the NEC as for a code reference.
rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
Yes, but what is the rating of the fire wall? My guess a 2 hr wall. Only the OP and inspector knows.
The OP did mention the panel is mounted ON the wall. The protection would still be the same.
cadpoint
Senior Member
- Location
- Durham, NC
Just FYI
NC works under IBC 2018, but I forgot what the active year they're using. Which is different from the NFPA adoption cycle!
I'd be sure to ask that if in fact you need to paint it!
NC works under IBC 2018, but I forgot what the active year they're using. Which is different from the NFPA adoption cycle!
I'd be sure to ask that if in fact you need to paint it!
- Use of fire walls to create separate buildings is now limited to only the determination of permissible types of construction based on allowable building area and height.
- The minimum lateral load that fire walls are required to resist is five pounds per square foot.
2hr fire wall. I’ve mounted hundreds of panels on them via a dozen different ways, this is the only inspector to ever say a thing.
rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
I get that. The panel is mounted ON the wall and not IN the wall, correct?
If that is the case, the inspector is wrong.
Ron
Well if he has a valid reason let's hope he doesn't make correcting all the ones the others missed retroactive.
You have penetrated the membrane so there is very possibly a UL problem. The design documents should have the wall type (not just fire wall) and you can research it from there with the Orange Books.
At some of the hospitals I did in NC there was a lot of things we had to do when mounting on rated partitions and walls.
Once again, ask him what he is enforcing.
rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
Exactly. I agree!
Ron
Ron
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
I can't see mounting to the sheet rock as a secure means of attachment for a panel enclosure.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Two layers of 5/8" rock is pretty strong. We almost always use strut for panels but if it didn't weigh much I wouldn't hesitate to mount it to the rock.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
The only thing I could find was some references to telecom industry standards, which of course are not code. Sounds like a situation where it's "cite the code or hit the road."
Curious as to your mounting method. Toggle bolts?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Four 1/4-20 toggle bolts will hold quite a bit of weight.
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