I'm figuring on adding a new circuit breaker, and I've spent some time looking into this. I'm almost at the point where I know I can do what I need to do, and have read as much safety material as I can get my hands on. As a side note, I've added lights to an existing circuit, and rerouted some other lights to another circuit, so I'm Ok for that part kind of stuff.

Basically it sounds like you attach your neutral wire to the neutral bus, and the ground wire to the ground bus. But in my box, there is no real differentiation between where the neutrals and grounds are attached. I've followed some of the cables coming in, and the white is attached to the same bus that the ground is, basically one under the other. Only the only real separation is when the circuits are on the left or the right of the box.

Is that normal / Ok? This is an older house who's panel was upgraded from a fuse box about 10 years ago (and none of the circuits were labeled). For what it's worth, it's a CH box with 100 amp service coming in.

Hope this all makes sense. Thanks.

If the panel you have has the main breaker in the panel, then having the neutrals and grounds on one bar is fine. If there is another main breaker remote from the panel, then not allowed.

Good question.

Thanks. It is the only panel in the house, though I may eventually upgrade it to 150 with a sub, but I'll deal with that at a far future time.