INDUCTION MOTOR STARTING SYSTEM Russian patent published in 2005 - IPC

FIELD: electrical engineering; ac drives for all industries.

SUBSTANCE: newly introduced in induction motor starting system are three-phase switching unit and three pairs of normally open contacts of electromagnetic starter connected in parallel with phase switches of main switching unit. Electromagnetic starter is provided with two additional contact pairs. First normally closed contact of pair is connected to power circuit of control unit and through normally closed STOP button, to one of phase leads of supply mains. Second normally open contact of pair is connected to first terminal of electromagnetic starter relay and to common point of STOP button and first normally closed contact of electromagnetic starter. Second terminal of electromagnetic starter relay is connected to supply mains neutral lead and the latter is connected to ground terminal of control unit. Inserted between first contact of electromagnetic starter and power circuit of control unit is normally open contact of control-unit magnetic starter relay.

EFFECT: stepless starting and enhanced reliability in continuous running mode.

1 cl, 3 dwg