I already asked this. But I have to toss that whole thread.

We had bought the model home & I just moved here. Next to us was the lot that they used as a parking lot for the model, that now they had put up this new house and all their electrical box was open and everything and the same model house. So I took pictures there since it was breaker boxes, main panel was all open.

I was looking to see if there’s a way to add a breaker between the Main and the panel inside to hook a type one surge protective device to. Everyone determined that the way the set up was there was no room in there to do something like that without replacing the entire box etc and wasn’t worth doing all that. Agreed!

Except I looked and that's not what we have on our own home. We don’t have a meter but up against a small box that there’s no room for anything other than the main breaker. We have this:

main shutoff main breaker SquareDbox enter image description hereenter image description here

  • How much space is available to the left of the existing main disconnect? Aug 31, 2021 at 11:42
  • Linked the original question for ease of reference
    – FreeMan
    Aug 31, 2021 at 11:48
  • 1
    Photos added with measurements. The outside outlet box is right by the punch outs, but I guess it can be relocated. There’s also punch out below that box.
    – hometech99
    Sep 1, 2021 at 16:16

2 Answers 2


The question is different but the answer is exactly the same. This breaker does not provide any location to attach the wires from the SPD.

The only difference is this is a discrete main breaker, not a meter-main, so it will be a great deal easier exchanging this unit for one that does what you want.

That being a main-breaker service panel with thru lugs (but without the meter pan).

The power company need only pull (or remote disconnect) the meter, no need for a bucket truck.

  • Found it on eBay… Somebody got smart realize people need this stuff..They take a outdoor 200A panel for QO that has 200A main breaker, eight spots, then 200A thru lugs to go to interior panel.. they pre-install a generator interlock, 50A breaker for generator, and a 50A generator input with it so it’s an all in one solution. Same size box that I already have up.I won’t have to run 6 gauge cable into the house through walls for a transfer switch by the interior box and all that. In the retirement community next-door is a master electrician that does work for people in the neighborhoods here.
    – hometech99
    Sep 1, 2021 at 19:52
  • @hometech99 You can buy anything on eBay... that doesn't mean you should. Anything you use has to be UL listed as-built. However, if the combination as "knocked together" is UL listed, you are all set. Even better, Square D has only a limited number of enclosure (box) sizes. If the assembly uses the same box (enclosure) as the existing, you don't need to pull the enclosure off the wall, just swap innards. Easy bolt-up. I could see someone simply buying all UL listed pieces from Square D, assembling them, doubling the price and posting them on eBay. Sep 1, 2021 at 21:30
  • The thing is, it is the same outer box. It’s all Square D.
    – hometech99
    Sep 2, 2021 at 0:48
  • Take a look on eBay. Item 334076850044
    – hometech99
    Sep 2, 2021 at 1:00
  • 1
    @hometech99 thing is, the box you are looking at is actually wider than the box you have -- the Q2200RBE is only slightly over 7.5" wide, while the QO1816M200FTRB is full loadcenter width at 14.75", and thus would hang slightly over the existing backerboard unless the nipple from the meter is shortened. The best option for fitting in your existing space would be a GE TM820RCUFL at 12" wide... Sep 2, 2021 at 2:40

box box box

Done. Main shutoff plus Generator input with interlock plus Whole house SPD. First Surge is rated Nema 3 I think, but even instructions say if weather an issue, to enclose. So the clear box is nema 4

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