DEVICE FOR PROTECTION FROM PHASE SWITCHING OFF OF INDUCTION MOTOR

摘要

The device is applies to electrically driven submerged pump units in farming and industry. It improves the working safety of submerged induction motors and expands the range of applications in terms of the type of connection of the stator windings. This is achieved by controlling the current at one of the phases of the motor and by switching it off in case this current deflects above or below certain preset values. The device consists of a sensor for the current (1), an amplifier (2), a rectifier-filter (3), comparators (4 and 5), separating diodes (6 and 7), a time delay circuit (8), an intermediate relay (9) and a magnetic starter (10).