PHASE-FAILURE PROTECTIVE DEVICE FOR TROUBLE-FREE OPERATION OF INDUCTION MOTOR Russian patent published in 1996 - IPC

FIELD: electronical engineering; phase-failure protection of induction motors. SUBSTANCE: device has capacitors 11 and switching members 4; in addition, it is provided with two diode rectifiers 10, 20, auxiliary relay 12, and second starter 15; coil of auxiliary relay 12 is connected between neutral points of supply mains and stator winding, its closing contact 18, between one of coil leads of second starter 15 and common point of cathodes of three diodes of rectifier 20 whose anodes are connected to phase leads of supply mains after closing contacts of first magnetic starter 3. Coil of second starter 15 is inserted between neutral point of stator winding and one of common points of parallel-connected contacts of auxiliary relay 12 and second starter 15; coil of first starter 3 is connected between neutral wire lead of supply mains and common point of three diodes of rectifier 10 through circuit of series-connected START-STOP button 8, 9 and contacts of thermal relay 7; anodes of three diodes are connected to supply mains phase leads; capacitors 11 are connected to phase terminals of stator winding in delta. EFFECT: improved reliability of protection. 1 dwg