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Marc Schneider
01-22-2008, 4:41 PM
I'm rewiring my basement shop to provide additional circuits for some new tools.

If I put furring strips on the cinderblock walls leading to the receptacles, can I avoid having to run conduit for the wiring. This is what is currently done in the basement, but I know that there are some code violations (which I'm in the process of fixing prior to the inspection) and I'm not exactly sure what the National Electric Code calls for here.

Rob Russell
01-22-2008, 5:45 PM
The requirement is that NM be protected from damaged. If you're running the NM down the face of the furring strips, that could be considered "subject to damage" from something leaning or falling against the wiring.

I'd ask your inspector what they require. If they say that running the NM down the side of the strip is all you need to do with exposed NM wiring, then you're OK.

You can use conduit to "sleeve" NM for the part where it's running down the wall to protect it from damage.

Art Mann
01-22-2008, 6:18 PM
I would be shocked if an inspector let you get away with that.

Rod Sheridan
01-22-2008, 6:19 PM
If you don't want to use NM (or aren't allowed to), you could use BX........Rod.

John Canfield
01-22-2008, 6:25 PM
It all depends on your local code. Call and talk to your electrical inspector and they will most likely be glad to volunteer information; or your code authority might have information on a web site.

In Florida (we currently live in central Texas), the electrical code changed four or five years ago (maybe longer) for garages. Wiring had to be in conduit up to so many feet in the air (don't know the number.)

Makes sense - exposed NM is subject to damage if exposed in an area where people are present. Kind of a long-shot of any harm actually happening, but our country seems bent on protecting us from ourselves.

Jim Becker
01-22-2008, 7:17 PM
Marc, welcome to SMC!

Around here, one must "sleeve" the NM drop in conduit down the exposed wall as Rob mentioned. Even if that isn't the rule, it's not expensive to do and makes good sense from a practical standpoint, IMHO.

Rob Russell
01-22-2008, 10:15 PM
I would be shocked if an inspector let you get away with that.

"Shocked" ... got the pun ... if an inspector let you get away with what? Running down the side of the furring strips? Sleeving the NM-Cable?

Jeffrey Makiel
01-23-2008, 7:07 AM
It sounds like a job for either conduit or BX cabling. BX cabling is much easier to work over conduit...especially if you have the hand tool that cuts BX (usually about $30). There is also aluminum cased cable that looks like BX but is aluminum. However, I don't know if it would be sufficient.

Also, you may wish to check if the electrical outlet boxes must stand off the block wall with a wood shim or board due to moisture issues being tight up against the block. Also, there is likely a minimum height requirement above the floor for basements outlets which is much greater than the usual 12" to 14".

Lastly, I recommend that you don't skimp on duplex outlet quality. Home Depot and Lowes sells cheap stuff and good stuff (contractor grade). The cheap stuff will crack. It's almost a given. And if you're using all metal stuff (boxes, conduit, BX, etc), it all must be grounded.

-Jeff :)

Prashun Patel
01-23-2008, 8:29 AM
Marc, welcome to SMC!

Around here, one must "sleeve" the NM drop in conduit down the exposed wall.

Same here in Cranbury, NJ.

I was counselled that for short runs, heat dissipation is not an issue, so it's ok to have Romex in a conduit. If you need longer protection of the cable than 6ish feet, I think u need wires without the outer sleeve.

Marc Schneider
01-23-2008, 9:24 AM
Thanks. I'll call the inspector and ask, but I'll probably run conduit down the wall, even if it isn't required as that sounds like the safer thing to do.

I'm also assuming I need to run conduit between the main panel and the subpanel I'm installing, right?

Rob Russell
01-23-2008, 9:41 AM
I'm also assuming I need to run conduit between the main panel and the subpanel I'm installing, right?

Not necessarily. You should be able to run NM or SER depending on the size subpanel you're installing. You want to put the subpanel on plywood that's mounted on something like 2x4's that are attached to the concrete. The subpanel feed can come out the top and go right up the the ceiling joists for the run over to the main panel.

Prashun Patel
01-23-2008, 9:54 AM
I'm also assuming I need to run conduit between the main panel and the subpanel I'm installing, right?

How far is the sub from the main?

Marc Schneider
01-23-2008, 10:00 AM
About three feet. I'm putting the sub right next to main. So would it be okay to run 6/3 NM directly between the two panels (attached to plywood). It seems wasteful to run the cable up to the joist and back down again.

Rob Russell
01-23-2008, 10:18 AM
About three feet. I'm putting the sub right next to main. So would it be okay to run 6/3 NM directly between the two panels (attached to plywood). It seems wasteful to run the cable up to the joist and back down again.

If the 2 panels are next to each other, there is no need to run up and down.

FYI, #6 NM will be limited to a 55 amp subpanel - you can't run a 60 amp subpanel with 6-4 NM. If you want a 60 amp subpanel, run a short piece of conduit (straight across is easy to do) and pull #6 THHN/THWN.

Rob

glenn bradley
01-23-2008, 10:25 AM
Where I am the wire must run at least 1 1/2" behind the rear of the wallboard or other covering. In my case the firring strips would have to be at least 2 - 2 1/2" deep. Not really firring strips anymore.

If you have similar requirements I would say conduit would cost you the least floorspace due to increased wall depth. Just my .02.

glenn bradley
01-23-2008, 10:26 AM
I'm with Rob. My panels connect straight across via the bottom punch-outs.

Marc Schneider
02-01-2008, 10:01 AM
Ok, so I'm planning on running PVC conduit down the walls to the boxes, but I'm thinking of running NM through the ceiling joists over to where the conduit will run down the wall. Do I need to have a box at the top end of the conduit and switch from NM to THHN to run down the conduit? Can I just run the NM into the conduit and down to the box at the bottom?