Here's the guts of one of the three circuits. (Only #3 is wired at this time).
We cut into the 120VAC house wiring, between the breaker box and the loads (outlets).
The NC (normally closed) contacts allow the power to pass
normally.
But when the Inverter is on and the 15A breaker is closed, the relay coil is energized.
The relay disconnects the loads from the main breaker box (the grid),
and allows the inverter to feed those loads.
I have the time delay disabled, so power from the inverter turns on the relay instantly.
Here's what it looked like before the blizzard of 2011 hit us.
#3 box is finished.. But, the AC input from the inverter has not been wired into the little breaker box yet.
The inverter (and bank box) have not been moved into their final resting place yet.
I will likely use a 20' extension cord for testing..