Your motor start at 4 times per hour : It consume in general 7 xIn per start during a court time +15min x4x In per hours
Determination of In:
In = P motors/ (U motors x Square(3)*x cos phi)
*only on 3P motor
For one motor on 3P
In= 750 W /( 400v? x1.732…x0.8)= 1.36 Amps
At starting during few second : Icomsume = 7xIn = 9.52 Amps : P=9.52x400vx1.732x.8=5.28 KW during a court time (between 1 and
10 second is depend of utilisation of the motor :Its very different to use a motor for pumping or for Lifting.
for pumping : 7. For lifting : 14)
The difference is the time during the motor Start and the application for the motor.