Originally Posted by midwilshire
This doesn't answer your question, but I wonder if one of our electrical geniuses can help with something....
When the power went out, my dad used to cut the main circuit breaker and run a home-brew cable from the generator output to one of our normal GFI outlets in the house. All of the outlets in the house were charged thereby.
Is this risky business or a slick solution?
There are a four problems with this method:
A standard GFCI outlet is only 15 or 20 amps, so would only safely carry 1800 watts for 15 amps, or 2400 watts for 20 amps.
The GFCI circuit will probably not protect against a ground fault.
If plugged into a 120 volt outlet, you are only supplying one "leg" of the house circuit. Homes are wired 240 volts, with 120 volts from each leg to neutral. Power applied "backwards" to one leg will only power other 120 volt outlets on that same leg, usually about half the home outlets if wired properly.
If all the 240 volt breakers are not turned off, then if one of the 240 volt appliances turns on (range, furnace, water heater, etc.) it could be damaged by voltage applied to only one leg of it's supply, and if a high load, will trip the breaker for the outlet the generator is attached too.
I had a generator I used a few times, would turn off the main breaker and had a heavy extension cord that plugged into the 240 volt generator outlet the other end plugged into the dryer connection. The danger with that was that if the cord is plugged into the generator but the dryer plug is not plugged in, there would be 240 volts on the dryer end plug if the generator was running, likewise, if the dryer connection was plugged in and the generator plug unplugged, there would be voltage on the generator end plug if the main breaker was switched back on when the power returned. Just have to be very aware of this when using it. I have the generator here in TN now, and will add a connection at the power panel for it before winter since the dryer connection is too far away from where I would run the generator.
Another reasonably safe method would be to turn off the main breaker, remove the front of the breaker box, remove the wires from one of the 240 volt breakers that is large enough to handle the generator rating, wire the generator to that breaker, turn off all the other 240 volt breakers, start the generator, then turn on the breaker it is attached to. That will supply all 120 volt breakers in the home.
If you have a rather large generator, this will not work well, as you could only supply the home with the amount of amperage the breaker attached too will pass.