STAR-DELTA START CONTROL CIRCUIT FOR MOTOR

摘要

PURPOSE: To provide a star-delta start control circuit for motor which allows continuous operation of motor in delta connection with no trouble upon recovery from instantaneous power interruption. ;CONSTITUTION: A main electromagnetic contactor 88 and electromagnetic contactors 6, 19 corresponding to star and delta connections are connected with the main circuit of an induction motor IM. The motor is started in star connection through the use of a star-delta timer 2 and eventually switching is made to delta connection operation upon elapse of a predetermined time limit. A holding circuit for exciting the main magnetic contactor 88 under the throw-in conditions of the electromagnetic contactor 19 for delta connection is provided as a control means for sustaining delta connection of the motor and restarting the motor on condition that the time to be elapsed after instantaneous power interruption before recovery therefrom is within the reset time of the star-delta timer.;COPYRIGHT: (C)1994,JPO&Japio