Expert ForumsMotors and Drives

Topic: Re: How can I connect a new motor to same old motor connection?

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As I interpret this inquiry the motors are probably wye-start delta-run, with one being 380 volts delta-run and the other 220 volts delta-run.  If the new motor is rated 380 wye and 220 delta, it will need to be reconnected or rewound for use at 380 volts delta-run.The 220 delta 380 wye connection motor can be used as a 380 wye across the line start motor.  The winding would not be changed.  However, the application must be able to withstand the increased (by 300%) torque of the across the line versus wye-delta start mode.  Also, the starter must be capable of the current associated with across the line starting.  The wye delta starter is not reconnectable for across the line starting due to the higher (by 300%) starting currents.