Rockwell Automation 1391ES AC Servo Controller - Manual (Page 67)

Troubleshooting
Chapter 10
10-65
Table 10.B
General System Troubleshooting
Possible Cause
1. The velocity feedback, position feedback device or velocity command signal wiring is
incorrect or open.
2. An internal controller malfunction exists.
1. Velocity Loop Compensation or Gain potentiometer is incorrectly set.
2. Position Loop Gain or Position Controller accel/decel rate is improperly set.
3. Improper grounding or shielding techniques are causing noise to be transmitted into the
position feedback or velocity command lines, causing erratic axis movement.
1. The Current Limit pot is incorrectly set.
2. The Current Feedback Scaling is incorrect.
3. The system inertia is excessive.
4. The system friction torque is excessive.
5. Available controller current is insufficient to supply the correct accel/decel rate.
1. The controller has a malfunction
2. The controller is not enabled.
3. The power contactor is not energized.
4. Power transformer is supplying the incorrect voltage or none at all.
5. The motor wiring is open.
6. The motor or transformer thermal overload has tripped.
7. The motor has malfunctioned.
8. The motor coupling has malfunctioned.
9. The feedback circuit (motor to controller) is open.
1. 60 Hz line frequency may be present.
2. 120 Hz from a single phase logic supply may be present.
3. 180 or 360 Hz from other adjustable speed drives may be present.
4. Variable frequency (varies with motor speed) may be velocity feedback ripple or a
disturbance caused by gear teeth or ballscrew balls etc. The frequency may be a
multiple of the motor power transmission components or ballscrew speeds.
5. Recommended grounding per Appendix B has not been followed.
Condition
Axis or System runs uncontrollably
Axis or System is unstable
Desired motor acceleration /
deceleration cannot be obtained
Motor does not respond to a Velocity
Command
Presence of noise on Command or
resolver signal wires