I need to switch supply power from one source to a different one without losing power. I am designing a control system for a customer to run an induction heater. They want to run the system off a generator but it draws to much power during the initial heating phase. Once the item is heated they want to switch over to the generator. My initial thought is to have two contactors, one NO and one NC, feed by the same control wire. That way, in theory, they could never both be on at the same time.
Since they are not perfect ideal devices there is a good chance that they will both be on at the same time or there will be a delay. The control system is also powered from this so I really don't want a voltage spike but I also don't want to lose power and cause the controller to reset.
My question is what other components do I need to add to keep this safe and not lose power?