hi all,
i have a compressor , i want to design the power and control circuit for it
so i should determine the maximum opperating current of it
so i know that the max. opperating cuurent= input power/operating voltage
ist right?

 

Maximum current = maximum input power / voltage

Current will be higher when the motor is first starting up. This initial surge can be six or more times the current at running speed.

 

yes, the starting current = (6-7) times the nominal current.

 

yes. but i mean the max. op. current. becuase when you choose the C.B and contactor ou select it depending on the max. op. current no the nominal operating current.

 

You are correct. I would add an extra 20% or more above the inrush, just to allow for unforeseen circumstances.

 

yes thats right......