Attaching expansion panel to basement wall

[JHZR2]

I recently bought a 100 amp Cutler Hammer expansion panel for my electrical system. I need to attach it to the basement wall. The walls have very old parging on them with a steel mesh behind it. What is the best approach to mount the box? I was thinking of cutting a piece of plywood larger than the box and then attaching it to the wall with tapcon screws. I would then just screw the box to the wood with some short wood screws. I have to check code but I believe that I would bond the box to the ground lug that I would install.

Are tap con screws the right approach to attach the box to the wall? Do I need the world peace or is it better to mount the box straight to the wall?

 

[Tempest]

I put a sub panel on a piece of plywood 10 years ago and all is well. The plywood is over drywall so it's a little different than what you have.

I would guess that 2 or 3 coats of Thompson's on the backside would help with longevity.

 

[eljefino]

I see boxes on plywood all the time. Can't speak for it's code-ability, just a local custom. This "adapts" to cinder block walls etc. For bonus points you can paint the wood flat black.

 

[JHZR2]

Originally Posted By: eljefino
I see boxes on plywood all the time. Can't speak for it's code-ability, just a local custom. This "adapts" to cinder block walls etc. For bonus points you can paint the wood flat black.


How about rust oleum black epoxy??? I have some an old can of that in my shop.

 

[Zaedock]

Tapcon's are fine. I would cut a few strips of PT plywood, mount those to the wall, screw the PT plywood to the strips, and then mount your panel.

 

[Donald]

How about using a Ramset to attach it?

 

[JHZR2]

What is PT plywood and a ramset?

 

[doitmyself]

What is the mesh/parging applied to? Concrete? Stone?


"Do I need the world peace" ?

Yes, it makes all home improvement projects go better!

PT is pressure treated. I would question it's use (OCD) since today's version is quite corrosive and wonder if it could corrode your fasteners or even maybe the fumes might oxidize the electrical components.

ramset are concrete nails that are installed with a powder charge, maybe air.

 

[TooManyWheels]

Originally Posted By: doitmyself

PT is pressure treated. I would question it's use (OCD) since today's version is quite corrosive and wonder if it could corrode your fasteners or even maybe the fumes might oxidize the electrical components.

ramset are concrete nails that are installed with a powder charge, maybe air.


When you use Powder Actuated fasteners through Pressured Treated wood you are expected (usually by Code) to use the specially coated ones they make for that purpose.

 

[AandPDan]

Originally Posted By: JHZR2
I have to check code but I believe that I would bond the box to the ground lug that I would install.


Are you installing this as a subpanel? Off your main panel?

If so, you'll run 4 wires to it, 2 hots, neutral, and ground. Remove the neutral/ground bonding jumper (if installed).

 

[JHZR2]

Originally Posted By: doitmyself
What is the mesh/parging applied to? Concrete? Stone?


Above-ground our foundation is brick, but it is poured below grade. So figure concrete.

 

[JHZR2]

Originally Posted By: AandPDan
Originally Posted By: JHZR2
I have to check code but I believe that I would bond the box to the ground lug that I would install.


Are you installing this as a subpanel? Off your main panel?

If so, you'll run 4 wires to it, 2 hots, neutral, and ground. Remove the neutral/ground bonding jumper (if installed).



Yes, 100A subpanel, fed by a 2-2-2-4 cable.

 

[doitmyself]

Originally Posted By: JHZR2
Originally Posted By: doitmyself
What is the mesh/parging applied to? Concrete? Stone?


Above-ground our foundation is brick, but it is poured below grade. So figure concrete.


I can only offer anecdotal advice based on what I have seen. I see lots of panels mounted on plywood in wooden structures. But in concrete/block walls I always see them mounted directly to the wall. Contractors always elect for easiest and cheapest, but it usually works.

What would be the purpose of the plywood?

The Tapcon screws are diy friendly. I use the genuine product because I don't trust the knock offs (just me). While you can pre drill with a regular drill (especially just a few holes), a hammer drill is so much better.

If you are dealing with a rough wall surface, another idea is to mount two horizontal strips of uni-strut to the wall, then mount the box to that. That's a bit over kill, but would eliminate having any wood. Spacers (washers) behind the box would also work. Use galvanized washers (vs. zinc)if you want.

Unistrut is something everyone should be aware of. Only get the galvanized (IMO), not the painted or yellow zinc chromate.

I feel odd giving out any diy advice to you because the electrical work you talk of (3 way switches, etc.) boggles my mind. Beyond R & R, electrical gives me fits. I once spent days reading the code books about low voltage apps., trying to figure out what's correct vs. what is done by contractors...i.e, running low voltage near high voltage. The real world contractors often don't seem to follow code. Sorry for the rant. Carry on.

 

[eljefino]

If you're planning lots of romex runs up to the basement ceiling the plywood will give you something to staple to, if you oversize it and get it up to said ceiling.

Would it be possible to connect the two boxes with a 1.5" conduit? That would look impressive and be a sturdy install.

 

[JHZR2]

Originally Posted By: doitmyself


I feel odd giving out any diy advice to you because the electrical work you talk of (3 way switches, etc.) boggles my mind. Beyond R & R, electrical gives me fits. I once spent days reading the code books about low voltage apps., trying to figure out what's correct vs. what is done by contractors...i.e, running low voltage near high voltage. The real world contractors often don't seem to follow code. Sorry for the rant. Carry on.



Your advisement on all the DIY stuff is great and very much appreciated.

That stupid 3-way switch was faulty and my circuit was right to begin with.

Seems all my headaches in electric go back to low quality stuff.