Differance between actual and set point speed

[gh_ounie]

We have problem in our Siemins drive SIMOVERT MV type number 6SE8001 when we look the actual speed we find it more than setpoint speed and the gap between the actual speed and setpoint speed become less when inverter is running in low speed and become more in high speed .
If you have any idia about problem let me know.
With best regard

 

[OZEE]

How are you measuring the actual speed?

 

[DickDV]

Since you are referencing speed rather than frequency, I conclude that you are in closed loop or vector control.

If that is the case, I would display the drive frequency and compare that to the measured shaft speed using the motor nameplate data. From that, you should be able to determine if the motor is motoring (negative slip) or is being pushed into regeneration (positive slip). If your speed loop tuning is really loose, you might just find positive slip giving you more speed than setpoint.