To provide a starter for motor, wherein the terminals of a motor are prevented from being disconnected from a power supply when two taps of an auto-transformer are used and the taps are changed; a rush current is limited in stages; and three-stage acceleration is made possible.
The starter for motor supplies a motor with alternating-current power via the auto-transformer. The starter comprises a first contactor which connects the alternating-current power supply to the motor; a second contactor which connects the alternating-current power supply to the auto-transformer; a third contactor for tap change which is connected with the first tap of the auto-transformer; a fourth contactor for tap change, which is connected with a second tap of the auto-transformer via a reactor; and a fifth contactor for opening and closing the neutral point of the auto-transformer. Since the motor, the third contactor for tap change, and the fourth contactor for tap change are connected in parallel, a starter for motor, where when the two taps of the auto-transformer are used and the taps are changed, the motor terminals are prevented from being disconnected from the power supply, a rush current is limited in stages; and three-stage acceleration is implemented is obtained.
JPS6146195 | INDUCTION MOTOR POWER CONTROLLER |
JP2004064870 | INVERTER UNIT |
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