- The motor does not rotate or the speed is abnormal
After starting the spindle drive system, if the main motor does not rotate or the speed is abnormal, the possible causes are as follows
(1) The armature wire of the spindle motor is poorly connected or the phase sequence is incorrect. If the servo drive displays AL-02 alarm while the main motor is not rotating, it indicates that the command voltage has been added to the drive, but the actual motor speed does not match the given value. In general, check the phase sequence of the armature wire connection between the driver and the main motor.
If the drive does not display AL-02 alarm, check the drive command voltage input.
(2) The speed feedback signal is bad. Check the connection of the main motor encoder one by one against the connection diagram of the FANUC AC spindle drive system, and measure the waveforms of PA/PB and PAP/PBP.
(3) Improper parameter setting. Should focus on checking the drive parameter F01, F02 settings.
(4) Bad ROM or wrong version.
- Oscillation or noise during operation causes abnormal oscillation and noise during operation of the main motor due to:
(1) The motor is defective, such as a short circuit of the armature winding to the ground or a partial short circuit.
(2) The measurement feedback signal is bad. Compare the connection diagram of the NUC AC spindle drive system, check the connection of the main motor encoder one by one, and measure the waveforms of PA/PB, PAP/PBP.
(3) The drive control board is defective.
- There is abnormal noise when the motor is braking. For the 6S~26S spindle drive system, due to the regenerative braking method, the energy is fed back to the grid. When the braking energy is too large, in order to limit the braking limit current, the regenerative braking circuit needs to change the current waveform of the motor, resulting in abnormal noise.
Reduce the parameter F20 of FANUC servo drive and reduce the power limit of regenerative braking, which can reduce and eliminate the noise during motor braking.
- Speed overshoot or oscillation occurs when the motor is running, the possible reasons are as follows:
(1) Overshoot: The speed loop proportional gain is set improperly, and the setting values of parameters F21 and F22 should be increased.
(2) Oscillation: The speed loop proportional gain is set improperly, so the setting values of parameters F21 and F22 should be reduced.
- The possible reasons for the decrease of the cutting power of the spindle motor caused by the decrease of the cutting power are as follows:
(1) The ROM version does not match.
(2) The torque limit is set improperly or the external torque limit command is effective.
- Inaccurate spindle orientation exact stop positioning may cause the spindle orientation exact stop positioning inaccuracy. The possible reasons are as follows:
(1) The setting and adjustment of the spindle orientation exact stop unit are improper.
(2) The spindle orientation exact stop control board is defective.
(3) The spindle drive control board is defective.
(4) The spindle position encoder or magnetic induction detection switch is defective.
- Too long acceleration/deceleration time may cause the spindle acceleration/deceleration time to be too long. The possible reasons are as follows:
(1) The torque limit is set improperly or the external torque limit command is effective.
(2) The torque limit signal input receiving circuit is defective.
(3) The drive control board is not adjusted properly.
(4) The acceleration/deceleration time parameter F19 is set improperly.
