I just replaced my ZInsco panel with a new Square D QO panel. The effort to make the change wasn't that bad. However, the CH retrofit doesn't look like too bad of a deal. There's nothing magic about the "box" of the panel itself. Should be plenty of room, the Zin breakers were substantially larger than the CH ones if I remember.

Tell us more. Last time I needed a replacement Zinsco breaker, it was made by Challenger and was very expensive.

Given the likely low volume of a special 'kit' it might prove cheaper to just buy a new panel and throw away the box it came in.

The bus bar and other component listing is not dependent on the box it is installed in.

Tell us more. Last time I needed a replacement Zinsco breaker, it was made by Challenger and was very expensive.

Link for FPE version

I don't know where to find the Zinsco version but it's the same deal.

As you can see, it's about replacing the entire panel guts, nut just a single breaker.

I'm sure for NM-B connections, swapping in a whole Square-D QO panel OF THE SAME SIZE is not too bad, labor-wise, but what about if it's all EMT and RIGID coming in?

Should be plenty of room, the Zin breakers were substantially larger than the CH ones if I remember.

I think you're right, per se, but the Zinsco has all the breakers in a single column; each breaker spans both buss bars, though of course the single poles only contact one or the other. But that's far from the stupidest design feature, as most already know. GOTTA take measurements... the width might work out.

The bus bar and other component listing is not dependent on the box it is installed in.

Are ya sure? There's the location of mounting holes for buss bars, neutral bars, plus the BONDING of GND and neutral, etc. I kinda thought the whole PANEL SYSTEM got its listing as a unit, si/no?

Then there's issue of how long can you have the power off to do all this McGuyvering... ;')

You can drill and tap any holes you need.

There is no restriction on altering things like that.

There are even cutout boxes and panels that come without a single hole.

Everything is drilled and punched as needed in the field.

... that's good to know. I'd better also check the DEPTH of the lame-o Zin box.

Maybe I could actually do this over a 2-day period, incl. new wires pulled for certain code-violating branches, when family member is out of town... hmmm...