Tom Horne, Electrician wrote:

SNIP

Jim
You may be behind the curve here. There is an interlock kit available
from at least two major service equipment manufacturers that interlocks
the main breaker with a two pole breaker that controls power from the
generator. The kit cost around fifty dollars.


No, I'm well aware of them. The "kit" may be $50,
which gets you some mechanical parts, but that doesn't
address the complexity of the wiring that needs to be done
and it presumes that OP has the "correct" Main breaker in place.

They are a neat idea though and a good solution to the
whole house transfer switch problem if one were building
from scratch.

Jim