The above mentioned three phase motor uses 50hz, 655V-725V in star connection and 380V-420V in delta. The surply voltage is three phase 50hz, 420V..Now I would like to find out if its possible to start(connect) the motor using the star delta starter, seeing the voltage it uses in star is higher than the supply voltage?.
Also what method do i use to select and configure the three phase circuit breaker and overload protection?.
Sorry bad english.
Thanks
Also what method do i use to select and configure the three phase circuit breaker and overload protection?.
Sorry bad english.
Thanks
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The motor seems to have the proper ratings for star - delta starting.
The way that star - delta starting works is that the motor is initially connected in star and operated at a lower voltage than the full-voltage rating for the star connection. That results in a lower current in the initial operating speed range at the expense of lower available torque. Once the motor speed has increased it is switched to the delta connection. At a little higher speed, the current is not as high as it would be if full voltage for the delta connection had been applied to the delta connected motor at standstill.
You should purchase a starter that is designed for star - delta starting of a motor of the rating that you have. Purchase the circuit breaker as part of the package. The instructions for the starter should tell how to set the overload protection and the timer or other device that controls the transition from star to delta. If possible, purchase from a supplier that has information that you can download in advance. You should be able to get better advice from your supplier than you can get here.
The way that star - delta starting works is that the motor is initially connected in star and operated at a lower voltage than the full-voltage rating for the star connection. That results in a lower current in the initial operating speed range at the expense of lower available torque. Once the motor speed has increased it is switched to the delta connection. At a little higher speed, the current is not as high as it would be if full voltage for the delta connection had been applied to the delta connected motor at standstill.
You should purchase a starter that is designed for star - delta starting of a motor of the rating that you have. Purchase the circuit breaker as part of the package. The instructions for the starter should tell how to set the overload protection and the timer or other device that controls the transition from star to delta. If possible, purchase from a supplier that has information that you can download in advance. You should be able to get better advice from your supplier than you can get here.
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Connecting the motor in star would create an under voltage situation that could burn up the motor.
Select overloads for the nameplate current rating.
Select overloads for the nameplate current rating.