This is a typical "McMansion" generac pair of transfer switches. The customer thinks that having two 200amp panels is 400amp service. I detest them doing this because the service to the house is ALWAYS 25kva (100amp). And the generator is 24kw (100amp).

The issue is that code requires an outlet every 6' on the wall and they run out of spaces for branch circuits in a 200amp panel. This necessitates and second 200amp load center inside.

The folks at generac could feed their xfer from a single 4/0 cable from the meter can and THEN split into the two load centers. But then we couldn't sell that extra xfer switch could we?

This seriously complicates a future solar install.