Patent ID: 8129863

Claim:
An apparatus for connecting a plurality of generators to run in parallel, comprising: a plurality of plugs, each plug being connected to a generator output socket of a corresponding generator, wherein the plurality of generators are driven by internal combustion engines and produce single-phase current outputs; an output socket that is adapted to be connected to an electrical load; conductive paths that connect the plugs to the output socket, the conductive paths are merged to a common path at a junction before the output socket; a connecting path that interconnects the conductive paths downstream of the junction; a dummy load installed on the connecting path; a switching circuit that opens/closes the conductive paths; current sensors that are installed at each of the conductive paths to detect current flowing through the dummy load in each of the conductive paths; a plug disconnection detector that determines whether a first detected current of one of the generators is equal to or less than a first value indicative of a first current flowing through the dummy load when the electrical load becomes zero, and when the result is affirmative, determines whether a second detected current of the other of the generators through the dummy load is greater than a second value indicative of a second current when the plug connected to the one of the generators is disconnected, and determines that one of the plugs connected to the generator output socket of the other of the generators is disconnected when the result is affirmative; and a switching circuit operator that operates the switching circuit to open the conductive paths not to connect the generators to the electrical load when the disconnection of the plug is detected.