[stevehull]

I understand that grid tie PV systems do not operate when the grid is down. Logical to prevent back feed into the system killing a worker of they are on the lines.

Apparently, the inverters, string or micro, sense 50 or 60 Hz current at 240 V and cut off the inverter if that is not present.

That said, can you turn the system off (transfer switch) turn on a small generator to "trick" the inverters into thinking the grid is still there?

I know that it would now be necessary to use a dump load to rid the system of excess power.

I can easily construct 240 V dump loads from oven electrical elements (2 kW each). Saw such a system when I was recently out of country. Problem was I did not speak the language and could not communicate with the builder (no translator present). The dump load was actually a set of hot water tanks with resistive elements.

Steve