Regenerative Bus Supply Troubleshooting - Allen-Bradley Kinetix 5700 User Manual

Table 129 - Axis Troubleshooting (continued)
Condition Potential Cause
The motor connections are loose or open.
Foreign matter is lodged in the motor.
The motor load is excessive.
No rotation
The bearings are worn.
The motor brake is engaged (if supplied).
The motor is not connect to the load.
The duty cycle is excessive.
Motor overheating
The rotor is partially demagnetized causing excessive motor current.
Motor tuning limits are set too high.
Loose parts are present in the motor.
Abnormal noise
Through bolts or coupling is loose.
The bearings are worn.
Mechanical resonance.
Erratic operation - Motor locks into
position, runs without control or Motor power phases U and V, U and W, or V and W reversed.
with reduced torque.
Regenerative Bus Supply
Troubleshooting
Table 130 - Regenerative Bus Supply Troubleshooting
Condition
AC current appears distorted,
non-sinusoidal on oscilloscope.
Audible (loud) noise from regenerative bus
supply.
DC-bus voltage fluctuations.
These conditions do not always result in a fault code, but can require
troubleshooting to improve regenerative bus supply performance.
Potential Cause
AC voltage distortion.
Excessive boost voltage.
Current Saturation.
Ride through condition.
Load current (<50%).
Excessive bus stiffness.
Excessive boost voltage.
Notching on AC line voltage.
Current overload.
Cooling fans enabled when AC input power is applied.
Loop response.
Dynamic load change.
Voltage loop or observer bandwidths.
Normal voltage ripple of 1...2% or approximately 7...15V.
External bus capacitance not entered correctly.
Rockwell Automation Publication 2198-UM002G-EN-P - February 2019
Troubleshoot the Kinetix 5700 Drive System
Possible Resolution
Check motor wiring and connections.
Remove foreign matter.
Verify the servo system sizing.
Return the motor for repair.
• Check brake wiring and function.
• Return the motor for repair.
Check coupling.
Change the command profile to reduce accel/decel or increase time.
Return the motor for repair.
Run Tune in the Logix Designer application.
• Remove the loose parts.
• Return motor for repair.
• Replace motor.
Tighten bolts.
Return motor for repair.
Notch filter can be required (refer to Axis Properties dialog box, Compliance tab
in the Logix Designer application).
Check and correct motor power wiring.
Possible Resolution
Improve AC voltage waveform with isolation transformer or line reactor on input
power. Distortion from the utility cannot be addressed.
Reduce the BusVoltageSetPoint or set to automatic mode. See
Regulation on page 42. for definition of boost voltage.
Normal operation, distortion improves closer to rated current.
Normal operation, distortion clears once input voltage disturbance ends.
Normal operation, distortion improves closer to rated current.
Detune the voltage and observer bandwidths.
Reduce the bus voltage set point or set to automatic mode.
Add isolation transformer or line reactor to isolate from notching source.
Normal peak operation, no resolution needed.
Normal operation.
If changed, set loop response to medium (default).
DC-bus voltage transient is normal with a peak-load step change, but adding a
capacitor module can help reduce voltage transients and adding an external active
shunt module can help prevent nuisance over-voltage faults.
Optimal voltage loop bandwidth setting is 1/10 of the current loop bandwidth or
lower. Optimal observer bandwidth is >2x the voltage loop bandwidth.
Normal operation.
Enter the sum of all bus capacitance external to the regenerative bus supply into
the Logix Designer application. See Calculate System and External-bus Capacitance
on page 394 to calculate external bus capacitance.
Chapter 7
DC-bus Voltage
281