backfeeding a generator, settle a discussion
All legalities and codes aside (I already know this is illegal and not up to code, trying to get a buddy to stop doing this), when a generator is backfed into a 220 outlet (say a dryer/range outlet) to power household circuits during an outage AND the MAIN BREAKER is switched to the OFF position on the house panel, is there any chance (in a correctly wired service) for power to leave the house and go out into the grid, possibly zapping a lineman?
I say yes (as the main only disconnects the two incoming “hots” and not the neutral), he says no.
Thanks
J-
Replies
disregard found the answer
Electrical theory wise, he is correct.
J-
Yep, with the main breaker tripped and all the electrical gods smiling on you, no electricity will "escape".
The problem is that it's far too easy to screw this one up, one way or another. I have a masters in EE and have been working with electricity since I was about 4 years old, but even I'd be very reluctant to try backfeeding our house (which I know to be wired correctly), and would double/triple-check myself, put masking tape over the breakers, etc, if I were going to try this. Another house with a speckled wiring history would be even more iffy.
One major hazard that is often overlooked in the double-plug cord you use to make the hookup. In the "heat of battle" it would be very easy to forget that the thing was hot on both ends.
Simplest way to explain it to him; If a lineman hears a generator running or sees lights on in his house, he will not get his service restored untill the trouble crew knows he is not backfeeding the circuite they are working on.
That means they are going to pull his meter. They will then restore power to everyone else and he will have to wait untill another crew comes out to put his meter back in.
Even on properly wired generators with transfer switches, the crews want them off while they are restoring power to that home or group of homes.