Running a bigger Motor on a 320 drive

[troyphin1]

I Have an application where a larger motor has arrived on a pump.  The original motor was 1.55kw on a 1.55kw drive.  The new motor is 2.2kW.  I know in the parameters the drive states that it can run .18kW to 3kW.  The machine manufacturer says they would not recommend it.  Could someone give a quick rundown on is this is possible and what the impacts on the drive would be of running over size or undersize motors on a drive even within the parameter range.

[Bastian_Schmitz]

The important part is the motor current not the motor power. If the motor power is lower equal then the maximum constant current of the drive it will work. If the output current of the drive is lower then the current of the pump it will be problematic. In that case is maybe a use with a frequency lower then nominal frequency possible.

The 1,5kW drive (400V) could deliver 4,1A an IE3 Motor with 2,2kW need ~4,5..5A at full load.

[troyphin1]

So looking at the parameters for the drive it has default setting of 3.5A, for nominal current with a max of 6.1A.  The mtor plate states 4.68A.  Its doesnt have much head pressure so I doubt it will get near this.  Where does the 4.1A in your response come from?  This is all theoretical Im waiting on a new motor but maybe in a future emergency who knows.  Thanks

[Bastian_Schmitz]

The 4,1A are the maximum continuous current from the catalog for a 3ph 400V drive. On a standard centrifugal pump has the flow a bigger impact to the power consumption then the head pressure. A throttle valve in the discharge line could be helpful to bring the pump in the right flow.