Code is NEC 2017. My existing main panel has plenty of ampacity but few spaces, and thus, is totally full. I have several potential paths for an upgrade.
One involves fitting a subpanel and moving 4 circuits (2 double-stuff breakers) there, and adding circuits there.
The other involves outright replacing the main with a very fine 60 space main panel. No more space problems!
But what happens with AFCI and GFCI requirements? If this were a new house, nearly all my circuits would require it, but I am grandfathered. Will the "new main" scenario void the grandfathering and require that nearly all circuits be upgraded to that protection? Or can I just move over my old breakers and call it good?