In the transfer switch, there is a 100amp double pole breaker that backfeeds another pair of breakers in the main power panel. I can manually turn off the utility mains on all panels (completely independent of a backfeed situation), and then turn on both double pole breakers.
Thanks for the info David.
I have the same switch you have, my electrician also installed a set of 100 amp breakers in the transfer switch and fed that to a standard 200 amp service panel to overcome the 16 breaker limit.
I like the way they did yours, but I have a 600 amp service with several 200 amp breaker panels spread throughout the house and garage, I don't think it would work as well for my setup.
Brian