Re: Induction Motor

Spir Georges GHALI

Hamdullah said:

                           How to smooth start a 3-phase induction motor ?

Dear ;


When we want to smooth the starting of ” AC Induction Motor ” we can use the Electronic Starters where we have 2 possibilities, that are :

– By ” Variable Speed Drive “,  or :

– By ” Soft Starter “

The main difference between them is :

with ” Soft Starter ” we can only ” Run  &  Stop ” smootly the motor, but after running the motor will run absolutly at his nominal speed, where with ” Variable Speed Drive ” we have the same advantage, plus we can after running change the spped of the motor. So, if you don't need to change the speed the best solution is using the ” Soft Starter “, but if you should change the motor's speed you should use the ” Variable Speed Drive “.


Noting that :

– There's up to 630kW-415VAC  as ” Soft Starter ” or ” Variable Speed Drive “.

– The Vriable Speed Drives generate the Harmonics.