F7412 fault in Siemens V70 Drive indicates an incorrect Commutation angle. This means the drive cannot correctly determine the rotor’s magnetic position, often caused by a misaligned or damaged motor encoder.
Cause: An incorrect commutation angle was detected that can result in a positive coupling in the speed controller.
Possible causes:
- The motor encoder is incorrectly adjusted with respect to the magnet position.
- The motor encoder is damaged.
- Data to calculate the motor model has been incorrectly set.
- Pole position identification might have calculated an incorrect value when activated.
- The motor encoder speed signal is faulted.
- The control loop is unstable due to incorrect parameterization.
Remedy:
- If the encoder mounting was changed, re-adjust the encoder.
- Replace the defective motor encoder.
- Correctly set the motor stator resistance, cable resistance and motor-stator leakage inductance. Calculate cable resistance from cross-section/length. Check inductance/stator resistance using motor data sheet. Measure stator resistance (e.g. multimeter).
- With pole position identification activated, check the procedure and force a new identification procedure by means of deselection followed by selection.
