KEB COMBIVERT F5 Reference Manual page 153

LM25
Field Weakening
Speed
LM - Motor Data Parameters
This parameter provides a better adjustment of the field weakening torque
curve. Under certain situations, if the input voltage is sagging too low or the
motor has very high slip, it is possible that the voltage limit might be reached.
This can be confirmed by monitoring the Modulation Grade in the Diagnostic
Screen #2 or DG.10. If the modulation grade reaches 100% or more the drive
is operating at the voltage limit and potentially can cause poor control of the
motor.
To prevent this from occurring the drive has an adjustable torque curve which
prevents the voltage limit from being reached. The value of this parameter is
normally calculated when the motor data is loaded in the LM parameters. After
entering the data, this value can be fine tuned.
Torque
LC30
1.5xT
Rated
T
Rated
This parameter is not applicable to PM Synchronous motors and therefore
will not appear.
Torque Limit
LM24 LM25
Curve
Speed (rpm)
153