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Almot's avatar
Almot
Explorer III
Jul 31, 2014

Attaching insulated bus bar to metal box

Installing Midnite Solar short bus bars like these:


in aluminum breakers box - Big Baby Box from the same Midnite, like this:



One bus bar is shown on the photo, and there are mounting holes pre-drilled for it. There is enough room to install another bar - above or below the breakers.

The instruction for bus bar says "use sheet metal screws #10". There are holes in black/red insulators to put the crew, head-up, and pilot holes in the box wall. The box is 1/16" aluminum - ignore where it says "steel" on the diagram. It's aluminum, it says so on Midnite site, and magnet doesn't stick.

#10 sheet metal screw in 1/16" aluminum, really? Like it's going to hold. Being not an electrician, I'm puzzled. Ok, the shortest screw will still penetrate the wall that the box is installed on - 1/4" ply and whatever is underneath. So it will hold. So I'm mounting the "sandwich" of bus and box to the wall, and if I want to remove the box, I need to undo the bus bars. Then plywood wall will have 4 holes after bars, in addition to 4 holes after the box itself. Not that I plan to remove it soon.

Am I missing something here?
  • Almot wrote:
    There is enough room to install another bar - above or below the breakers.

    I don't know about that . . . my Big Baby Box got pretty crowded with just one bar:

  • Almot's avatar
    Almot
    Explorer III
    Son of Norway wrote:
    Screw them in from the back?

    I can, but this is not how they meant it. The holes in black/red insulators are big enough to put #10 screw through, and pre-drilled holes in the box wall (they only prepped it for one bus) are pilot holes, smaller than #10.

    If I screw it from the back, I would need at least #12 screws. And make sure they don't touch the metal bar.

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