I recently saw a small transfer panel at the local Menards which handled
4 or 6 circuits. It basically mounted near you existing panel. Each
circuit that you want to transfer is then routed into the transfer panel
first and then to the main panel. When you are in the transfer mode,
there is a mechanical interlock which prevents backfeeding the main
panel. If the home is wired with romex, the job is fairly easy ... with
conduit, a bit harder.

Matt wrote:

Hi,
In the event of a power failure I would like to be able to power my
fridge as well as my furnance... those are really the only two
requirements. Is there a cheap way to do this? Fridge, obviously I can
run an extension cord... but what about the furnance?

I don't suppose it's safe to 'backfeed' an electrical system.. ie flip
the main off, and then plug the generator into say a 20Amp outlet, and
then run the furnance through the backfeed of the electrical system as
long as I don't use anything more then 20Amp circuits?

~ Matt