4 ms·

That's assuming that your mains breaker is actually functioning, usually not too many of them get tested at 100-300A since the per-circuit ones trip first. Las

That's assuming that your mains breaker is actually functioning, usually not too many of them get tested at 100-300A since the per-circuit ones trip first. Last time I read up on backfeeding one of the common refrains was that flipping the main breaker on many homes still left one leg hot back to the transformer. Totally out of spec but common enough to be called out. Hence why a transfer switch is legally required if you're going to run your house from a generator/etc.

bluGill 9y ago
It isn't just the mains breaker. It is all the other breakers on your system. Your generators/inverter probably has a breaker someplace as well. I don't know how common the one hot leg thing is. I know that can buy a lockout device which is just a metal device allowing either my main breaker or one other breaker to be on: thus turning my entire panel into a lockout. That implies the one hot leg thing isn't common but I honestly don't know.