What would cause a pump to oscillate (or surge) up and down when ramping up to speed on the ATS48 soft starter?
All models, all serial numbers
Excessive motor slip
In the drC menu, reduce LSC. Generally, LSC = 30 will suffice.
LSC = Stator Loss Compensation
Oscillations are most common when controlling a motor with excessive slip.
Another option is to turn off the torque control. In the drC menu, set CLP = OFF.
Refer to the ATS48 Programming manual S1A37491