I'm going to upgrade my existing electrical service from 100 amps to 200 amps. Along with the service upgrade, I'll be moving the location of the service drop (part of a larger home remodel). I want to keep the existing 100A panel (which mostly serves old K&T and original NM spec wiring) as a subpanel. I'll add new circuits to the new 200A panel, and over time decommission the circuits fed by the 100A panel.
I'll add a 100A breaker in the new panel. But my existing panel has a non-removable main breaker (rated at 100A). Is this allowed?
Are there other considerations?