Repair-It

We've heard you must have interlocks to prevent back feeding the grid when hooking a generator up to the circuit breaker panel in a house. The risk, we are told, is that a line worker could think the line is not energized and your generator could kill him. This is exacerbated by transformers running the opposite way (as step up).

My question is, if a generator is really presenting voltage to the grid, to that line worker, doesn't that mean that generator is actually trying to power the entire grid? I would argue that it would overload instantly and that would not be sustainable for any real length of time. However, if the utility company has isolated the section of the grid that is faulty, and that is local enough, and people have shut off their loads as a response to loss of power, it is conceivable that the line worker could get a deadly shock.

It's just interesting because it requires a few things to fall in line for this risk to become a reality. And it makes me wonder how common it actually is.

Good point, never thought of it that way.

I still wouldnt want to test it.. But it makes sense. I doubt many people turn off their main breaker during a power outage.. But out in the boonies, it could be possible to have a break local to you only power a couple of houses. Or you could be at the end of the line. Since we dont have access to a circuit diagram that tells where the breaks are, it would be tough to predict if you would be powering other people's houses.

Agreed. I'm not saying it doesn't happen, or that I want to experiment. It's an academic argument that the risk is actually a lot lower than we've been lead to believe. In reality it doesn't matter if the risk moved down, because I'm still taking those precautions.