I have 6KW portable generator with a 240 volt cheater cord. It plugs into the generator and would be backfed into a 100 AMP secondary panel in my garage via 60 amp breaker for my welder. I would need to manually shut off my main breaker to do this. Definitely not to code but a lot easier and cheaper than installing a 200 amp transfer switch for something that hasn't been needed for 16 years.