Selection of Generator for Motor Starting With a Soft Starter

Hello Asitha

Please advise your Location and Country (easily done by you in your Member Profile, then it auto-updates through all your Topics and Posts, including this one)

Is there any other equipment to be connected to the Alternator?

Advise Voltage/Frequency of the motor you have on-site please.

What equipment is that Motor running?

Any other useful factors.

Reply here with and you may receive some assistance.

Kind Regards....

With Soft-starters, the general practice is to over-rate the DG by a factor of 2 i.e. to support start-up of 75 KW motor, 160 KW / 200 KVA DG should be sufficient. Moreover, in majority of the soft-starters, the ramp-up time can be varied upto 20 seconds or so.

Rgds

Sanjeev

I agree, a factor of 2 on the motor kW is a good general rule. So you would use a generator rated for 150kW continuous as a minimum.

You failed to mention the settings of the soft starter by the way, i.e. is that 2 seconds at 500% current, or is it 2 seconds at 350% current? If the latter, you MIGHT be able to get away with a slightly smaller generator, say 1.75 x the motor rating, but that would be taking a chance.