I've completed a beautifully (inspector approved) installation of a new 200 amp service panel to my home (upgraded from 100 amp). I have now strung a 0/0 underground aluminum cable in sched. 80 conduit from my barn to the main panel to connect a sub-panel in my barn to this new 200 amp panel.

How do I connect this rather large wire to the service panel? The heavy wire is too large for the existing neutral/ground bar. I assume there are breakers specifically for large wire like this? Are there lugs that can be installed on the neutral/ground bar for large wire?

Also, would it be feasible to run the large cable to a cut-off panel before going to the main panel, and then running smaller copper (#3) to the main panel?

I've completed a beautifully (inspector approved) installation of a new 200 amp service panel to my home (upgraded from 100 amp). I have now strung a 0/0 underground aluminum cable in sched. 80 conduit from my barn to the main panel to connect a sub-panel in my barn to this new 200 amp panel.

How do I connect this rather large wire to the service panel? The heavy wire is too large for the existing neutral/ground bar. I assume there are breakers specifically for large wire like this? Are there lugs that can be installed on the neutral/ground bar for large wire?

Also, would it be feasable to run the large cable to a cut-off panel before going to the main panel, and then running smaller copper (#3) to the main panel?

Oops. I mean a 4 guage aluminum (about the size of my pinky), not 0 guage as I said above. Nontheless, I'm looking for ideas on how to connect this large wire into a standard 200 amp panel.

The 200 amp panel should have lugs that will accept #4 wire. The line and neutral lugs are large enough to accept up to #4/0, maybe even 250 MCM wire, which al both much larger than #4. The neutral bar and equipment ground bar should have a couple of #4 lugs/ports for #4 wire.

If not, the panel manufacturer will offer an optional #4 lug that can be easily added to the neutral or equipment ground bar.