Hoo wrote in
:

The rotary switch

Make damned sure this switch is a BREAK before MAKE affair or it will soon
be welded shut!

I like the contactor approach, myself. You plug in shore power, the
contactor closes hooking shore power to the panel until you unplug shore
power, when it connects your inverter to the panel.....automatically....

No runs, no drips, no errors, noone left on 3rd base....goofproof.

--
Larry