dear sir, after aututuning the motor to inverter ,how to adjust the s-curve parameters for smooth ride of lift(acc1,acc2,accgain,dec1,dec2,decgain) what is this s-curve ,rcurve,u curve please tell us about the other parameters of the drives for deserving smooth ride we are using VVVF drive with encoder feedback in close loop please give details of the various types of encoders and precautions while installing it regards M V Apte AMit kolekar(amit_kolekar@hotmail.com)

-- mandar apte (mvapte@rediffmail.com), August 04, 2002

Answers

Elevator ride quality is influenced by many mechanical, electrical and tuning issues. If there are serious mechanical problems, the most sophisticated drive in the world cannot make them go away. A closed loop AC or DC motor control causes motor torque so that the encoder feedback will follow a desired rpm / velocity profile. Adjustments for ft/sec(sqared) and ft/sec(cubed) affect only the accel & jerk smoothness of the velocity reference. Poor encoder mounting or electrical interference will cause erratic results. Incorrect adjustment of velocity loop gains (P I D or Inertia) can also cause poor performance. See the Magnetek website www.elevatordrives.com for good information about set-up and tuning of Magnetek AC and DC drive products.

-- Don Vollrath (dvollrath@magnetek.com), August 05, 2002.