Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX - Manual (Page 312)

12-30 Troubleshooting
Encoderless Troubleshooting
Problems If you are having problems with encoderless mode, refer to this table
for possible solutions before calling for help.
If: Then you should:
The motor will not
accelerate or does not
start smoothly
• Increase the bandwidth in Spd Desired BW
(parameter 161). If the bandwidth is too low, the motor
may not accelerate, although the current increases to
current limit.
• If the regen power limit is 0, increase it to at least -5%.
• Increase the torque and current limits to the maximum.
• Increase the value of Kp Freq Reg (parameter 178).
The motor oscillates
after it is up to speed
• Decrease the bandwidth in Spd Desired BW
(parameter 161) if the process will allow. If this does not
help, depending on your application, you need to either
increase or decrease the value of Error Filter BW
(parameter 162).
The inverter trips on
absolute overspeed
during starting
• Increase the acceleration time.
• If the overspeed occurs during a fast acceleration,
increase the value of Kp Freq Reg (parameter 178) until
the trip stops occurring.
• Increase the bandwidth.
• If the overspeed occurs during a reversal, increase the
deceleration time (slower deceleration).