The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Calling all Non-US members!! (Non-US only)
by aussie240
Today at 02:39 AM
Photo Upload Tutorial
by DanK
Yesterday at 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
2 registered (DanK, LongRunner), 228 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 3 1 2 3 >
Topic Options
Rate This Topic
#100764 - 01/02/07 04:34 PM Panels in basement
FlatLine Offline
Junior Member

Registered: 01/01/07
Posts: 7
Loc: Frankfort, Ky, USA
our inspector requires panels mounted in basements to be seperated from the concreate wall by plywood. Does anyone know in the code where it requires this? Also, If the wall is studed and the panels are mounted to the studs with the concrete behind them, would this still require the plywood?

Top
2014 / 2011 NEC & Related Books and Study Guides
#100765 - 01/02/07 04:37 PM Re: Panels in basement
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Not an NEC requirement.
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

Top
#100766 - 01/02/07 05:08 PM Re: Panels in basement
ShockMe77 Offline
Member

Registered: 06/11/05
Posts: 823
Loc: Rahway, New Jersey
I would ask the AHJ wich article in the NEC he is referring to if he's requiring you to do this. I did some looking around at article 408, and from there one of the articles referred me to 312.2 (A). As long as the panel is elevated 1/4" off the concrete wall I don't believe there is a violation. However, unless a panel is mounted between two studs I ALWAYS use a sheet a plywood as a barrier from the concrete wall. Think corrosion.

Top
#100767 - 01/02/07 05:45 PM Re: Panels in basement
FlatLine Offline
Junior Member

Registered: 01/01/07
Posts: 7
Loc: Frankfort, Ky, USA
thanks alot, It's probably just a local requirement due to the corrosion like you stated.

I have seen the 1/4" rule before, I guess with no studs the plywood gives the 1/4" and the corrosion.

Top
#100768 - 01/02/07 06:11 PM Re: Panels in basement
ShockMe77 Offline
Member

Registered: 06/11/05
Posts: 823
Loc: Rahway, New Jersey
I had an inspector once who wanted sheet metal placed behind the plywood!

Anyone have any idea why?

Top
#100769 - 01/02/07 06:37 PM Re: Panels in basement
HLCbuild Offline
Member

Registered: 12/05/04
Posts: 206
Loc: Herndon,Va USA
Termite shield...you wouldn't want those termites to eat the plywood and get corrosion on their little bodies would you!

Top
#100770 - 01/02/07 06:45 PM Re: Panels in basement
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
The sheet metal protects the plywood (vapor barrier) and the plywood protects the panel?
I would think VisQueen would do the same thing. If the basement walls are damp you can make the 312.2 (1/4") rule work.
_________________________
Greg Fretwell

Top
#100771 - 01/02/07 06:54 PM Re: Panels in basement
ShockMe77 Offline
Member

Registered: 06/11/05
Posts: 823
Loc: Rahway, New Jersey
I figured the sheetmetal was for some sort of protection for corrosion, but why isn't it in the code somewhere?

Or maybe the AHJ was using 300.6 as his justification.

Anyway, I only did it a few times and no one has enforced it since.

Gfretwell, you're an inspector, right? Do you enforce this?

Top
#100772 - 01/02/07 06:59 PM Re: Panels in basement
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I didn't do that much residential. In commercial the enclosures were usually on strut. Also we don't have basements.
_________________________
Greg Fretwell

Top
#100773 - 01/02/07 07:23 PM Re: Panels in basement
ShockMe77 Offline
Member

Registered: 06/11/05
Posts: 823
Loc: Rahway, New Jersey
I forgot that basements are non-existant in some areas of the country. I just got back from the Carolina's and they didn't have any down there either. I've become so accustomed to them that I could not imagine not having one. Where would I store all my crap? LOL.

By the way, isn't all concrete considered to be a damp location? And why don't inspectors enforce 4x4 metal boxes on concrete walls be mounted on some sort of wood? If we do it for panels, we should also do it for any metal electrical box.

Top
Page 1 of 3 1 2 3 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals