PROTECTIVE DEVICE FOR PIECES OF HIGH-VOLTAGE ELECTRICAL EQUIPMENT Russian patent published in 2000 - IPC

FIELD: protection of high-voltage pieces of equipment and circuits in passenger cars. SUBSTANCE: device has series-connected high- voltage fuse, first current derivative transducer incorporating relevant meter, protective contactor with control unit and contactor operation warning element at high-voltage equipment input. Output of first-derivative transducer is connected to input of comparator provided with two separate outputs. First output of comparator is connected through inhibit element to input of protective contactor control unit. In case of emergency, signal arriving from comparator second output prevents passage of that from its first output by means of inhibit element. Signal coming from delay unit output arrives in certain time upon operation of protective gear on locomotive and causes disconnection of protective contactor. Upon reclosure of high-voltage line only defective circuit remains open. EFFECT: provision for selective protection of car and locomotive. 1 dwg