Before you say "You could launch your generator to the moon" please read the whole post.
I have a 3500 watt portable generator that I'd like to use as backup emergency power for a couple of circuits in my house. The generator does not have a 240v output. It only has two 120v outputs. What I was considering doing in the event of an extended power outage is to connect the generator to an outside 120v outlet with a double male 30amp extension cord and backfeed power to select circuits in the house through that outlet. I know there are catastrophic risks if it's not done correctly so here is my plan step by step.
1) Turn off main circuit breakers to prevent power from backfeeding the grid.
2) Turn off all circuit breakers to prevent overloading the generator.
3) Connect the generator to the outlet while the generator is NOT running.
4) Start the generator.
5) Turn on the one circuit breaker for the outlet that the generator is connected to. This should start backfeeding power on that circuit.
6) Turn on ONLY the breakers for my "emergency" circuits. This would consist of 1 circuit that only has my gas heater connected to it, to power the igniter and blower.
7) Turn on one other circuit that has only a refrigerator connected to it.
8) Turn on one more circuit that will have only a lower power lamp (led bulbs).
The total current drawn should never exceed 15 amps even when the refrigerator first kicks on and should be well within the limits of the generator, extension cord, and circuit that I am back feeding power through.
When I see the neighbors have power again I would disconnect it this way.
1) Shut off generator and unplug the cable from the generator side first, then the outlet.
2) Turn off all circuit breakers
3) Turn on the main breakers
4) Turn on all circuit breakers.
Again I know there are dangers if this is not done 100% correctly including fire and electrocution of the guy hooking it up (me) and someone working on the utility lines (if I forget to shut off the main breakers). My only question is "Will this work as described?"
<donning flameproof suit>