I'm getting ready to frame out a wall in my basement that has an electrical subpanel. I would like to move the panel out an inch or so, so I can frame around it and it will be flush with the finished wall. There is plenty of room and extra cable above so that I shouldn't need to rewire anything. My original plan was to remove cover, frame around it, turn off power, unscrew panel and slide it forward, reattach to studs, replace cover, turn power back on. But, the builders attached it with a ramset directly to the concrete! So, does anyone have any ideas on how to get that thing removed without having to disconnect all of the wiring to get a prybar in there? There might be enough clearance to get a sawsall blade behind the box and cut the nails from there, but I wouldn't bet on it. Any other ideas would be much appreciated.
Powder-actuated gun nails are extremely hard. You don't want to have to cut them with a saw, and you probably won't have room anyway.
Get yourself an angle grinder with an abrasive wheel. Bracing your hands well against the box, carefully grind away just the heads of the nails. You should then be able to pull the box off the nail shafts.
Obviously, take all necessary precautions when working around electrical current, and use eye and ear protection.
Caveat: Be sure that you have enough length available on your primary conductors to make the move you have planned. You may also be required to install conduit behind the box, where the wires are exposed.
You could drill around it with a 3/8 hole saw with the pilot bit removed, even a 1/4" might work. Don't push too hard on the washer so it doesn't come free. If it does come free drill a hole in it off to the side and insert a nail to stop it from turning. Dremil is expensive if you don't already have one and could take a while. A grinder is a little cumbersome working in a panel. All will work just adding some options.
There seems to be some different ideas between pros about how to do this, according to the following link from 2013.
If you ignore the sub-conversation about using these nails in the first place:
At least one person suggests grinding them down, but there's also someone that says it won't work.
One poster suggests using a small prybar to pop the heads off or "simply" pull the nails out.
Another poster suggests drilling out the heads, which was my first thought, but another person says that won't work. Evidently the nails are case hardened to be able to penetrate the concrete.
I'd think a grinder would be your best bet, but if it doesn't work, try the drill option, with some really sharp bits. Leave the prybar for last, as that can shoot nail or concrete at high velocity any/everywhere.
As always, be safe and use the appropriate personal protective equipment (PPE).
Oh, and good luck, too! It sounds like you're going to need it.