i'm really didn't understand , about how to configuring time for starting motor . in my project is 1 phase motor using three part of resistances (with Direct OnLine method) . my problem is how to determining time starting value , is it any calculation method ?? could anyone help me please...cause it is very urgently , if anyone could share , can sending me a details to my email

Hello angga1
Welcome to the forum
The starting time is dependant on the motor characteristics and the load characteristics. You need to keep the voltage reduced as long as the motor continues to accelerate. If you switch too early, the current will go very high. If you switch too late, the start time will be prolonged and the motor will heat up.
Best regards,

It means that the starting time must be refer to the motor maker?

Dear Jacky,

No, if load is coupled with motor through a magnetic clutch and motor starts independently, then you can say "starting time must be refer to the motor maker". If motor is direct coupled with load then Mark's comments would be applied "The starting time is dependant on the motor characteristics and the load characteristics".

Marke

Can you please explain why this is? I am having a similar problem of switching time and am trying to learn the science behind what you just explained above. I am having a hard time understanding why switching too early causes current to go high?

Thanks for the hlep.