To prevent interruption of power in a load, in the case of switching generating power from a generating set to commercial power.
In the case of switching from generating power of a generating set 3 to commercial power, first a switching signal is generated to perform switching action of changeover switches 6, 7, 8. After the switching action is completed in all of a plurality of the switches 6, 7, 8, a stop permitting signal is generated from a stop permitting signal generating means, from a changeover switch device 5. The generating set 3, by receiving this stop permitting signal, breaks a switch 27 to stop supply of the generating power. Accordingly, after a load is connected to a commercial power source 1 by the changeover switch, supply of power from the generating set 3 is interrupted, so as to prevent generation of power interruption in the load.
IWATA SHIN
FUKUDA TADASHI
