As you may be able to tell from the photo, Zinsco was a manufacturer of inexpensive residential electrical panels. Zinsco panels were apparently popular in the 1960s, and were installed all over the place. The house on which we've placed our offer happens to have a Zinsco panel in it. Specifically, the panel pictured at right.
Zinsco and Federal Pacific are both red flags when it comes to electrical inspections. I don't know a lot about Federal Pacific, but I've done some reading about Zinsco.
Both panel manufacturers used non-traditional designs, ostensibly to lower production costs and provide a more flexible breaker mounting system. The Zinsco breakers snap directly onto two charged rails, and the unorthodox design often results in broken contacts and torched casings.
Zinsco also used a split buss design where the top half of the panel (pictured) is completely isolated from the bottom half. Unlike modern panels, there is no "main" breaker to throw—in fact, disabling the power to this home requires throwing six different breakers. This means that if you're unfamiliar with the layout, you'll possibly leave lots of live circuits.
Lastly, the Zinsco breakers are particularly reluctant to throw over, even when under serious load. Properly functioning circuit breakers will automatically throw when the lever is moved halfway through its travel. The Zinsco breakers (and especially the red 20-amp breakers, according to my home inspector) often won't throw over until they're past the 75% mark...if at all. The website linked above mentions cases where the breakers never threw.
So if you encounter a Zinsco (or Federal Pacific) panel, be damned careful and get it replaced pronto. Enjoy.
Are you going to be able to replace this yourself, or are you going to have someone come in and do it? Housing inspector find anything else bad? I had one done when I bought my house, and a lot of it was just little things, some of which I still havent replaced.
Unfortunately, to replace the panel, you have to remove the meter from its housing—which means I have to involve the power company, at the very least. And once that's done, the panel still has to be installed and wired up correctly, which although it's something I could probably handle, I'm not going to trust 100+ amps to "probably."
The inspector did find a number of other things, and I'll be surely fixing those one-by-one. Other big issues included some mold in the sheetrock immediately adjoining the electrical panel (so I'll take that out) and some warped and cracking siding along the south face of the house. It looks like I'm going to learn how to install siding, too.