The three-phase current ratings of 200KW and 90KW motors are approximately 400A and 180A;
Although it is star-delta starting, the influence of the starting current should always be taken into account:
Select the circuit breaker For 200KW, it is recommended to choose an air circuit breaker with a rated current of 630A, and for 90KW, it is recommended to choose an air circuit breaker with a rated current of 315A.
As for star-delta starting, the three contactors are selected to be 1.2 times, 1.2 times and 0.8 times of the motor rated current respectively; 0.8 times is the star contactor. The thermal relay should be 1.1 to 1.25 times the motor rated current. The motors in our factory usually directly use thermal relays equal to the rated current of the motor, and they always work safely and stably. You can refer to this rule for selection. You can choosesir domestic or foreign CJ20 series ABB, Schneider, etc. It is recommended to select the specifications from 200A 250A 400A 630A.
12*7.5/unit=90kw The starting current of a water pump is 8 times higher than usual
If it starts at the same time, it is of 90kw*8=720kw. You need to buy a 720 kW generator
If you start separately, you can use a 200 kW generator