F07412 — Drive: Commutation angle incorrect (motor model)

F07412 is raised when an incorrect commutation angle was detected that can result in a positive coupling in the speed controller. The monitoring compares the pole position angle delivered by the motor encoder with the angle the drive's motor model calculates, and it only becomes effective above the changeover speed set in p1752. If the comparison finds the difference excessively large — more than 80 ° electrical on servo drive objects, more than 45 ° electrical on vector drive objects — the drive trips with fault value 0; on vector drive objects, fault value 1 additionally reports an encoder speed signal that changed by more than p0492 within one current controller clock cycle.

• The phase sequence of the motor output phases is incorrect, e.g. two phases are interchanged.
• The motor encoder is incorrectly adjusted with respect to the magnet position.
• The motor encoder is damaged, or its speed signal is faulted.
• The angular commutation offset (p0431) is set incorrectly.
• The data used to calculate the motor model is incorrect: the motor-stator leakage inductance (p0356), the motor-stator resistance (p0350) and/or the cable resistance (p0352).
• The changeover speed for the motor model (p1752) is set too low; the monitoring only becomes effective above this speed.
• Pole position identification, when activated (p1982 = 1), may have calculated an incorrect value.
• The control loop is unstable due to incorrect parameterization.

1. Check the phase sequence of the motor and correct it if required — in the wiring or via p1820.
2. If the encoder mounting was changed, re-adjust the encoder.
3. Replace the motor encoder if it is defective.
4. Set the angular commutation offset (p0431) correctly; if required, determine it using p1990.
5. Set the motor-stator resistance (p0350), the cable resistance (p0352) and the motor-stator leakage inductance (p0356) correctly: calculate the cable resistance from cross-section and length, check the inductance and stator resistance against the motor data sheet, measure the stator resistance, e.g. with a multimeter — and if required identify the values again with the stationary motor data identification (p1910).
6. Increase the changeover speed for the motor model (p1752); the monitoring is completely deactivated when p1752 is set above p1082 (maximum speed).
7. With pole position identification activated (p1982 = 1), check the identification procedure (p1980) and force a new identification by deselecting and reselecting it (p1982 = 0 -> 1).

Note: For High Dynamic Motors (1FK7xxx-7xxx), the monitoring should if necessary be disabled for applications with a higher current.

The drive stores the fault value in r0949; read it as a decimal number. The decoding depends on the drive object type:

• SERVO, value 0: the comparison of the pole position angle from the encoder and the motor model resulted in an excessively high value (more than 80 ° electrical).
• SERVO, value 1: – (the manual assigns no text to this value).
• VECTOR, value 0: the comparison of the pole position angle from the encoder and the motor model resulted in an excessively high value (more than 45 ° electrical).
• VECTOR, value 1: the speed signal from the motor encoder changed by more than p0492 within a current controller clock cycle.

• r0949 (fault value) — read it as a decimal number to see which deviation tripped this fault.
• p0431 (angular commutation offset) — set it correctly for the encoder actually fitted.
• p1990 (encoder adjustment, determine angular commutation offset) — determines the angular commutation offset p0431 if required.
• p1820 (invert output voltage) — corrects the motor phase sequence in software instead of rewiring.
• p0350 (motor-stator resistance) — check it against the motor data sheet, measure it, or identify it again with p1910.
• p0352 (cable resistance) — calculate it from the cable cross-section and length.
• p0356 (motor-stator leakage inductance) — check it against the motor data sheet.
• p1910 (stationary motor data identification) — identifies the motor data again at standstill if the entered values do not match.
• p1752 (motor model changeover speed) — the monitoring is only effective above this speed; a value above p1082 deactivates the monitoring completely.
• p1082 (maximum speed) — the reference above which p1752 switches the monitoring off.
• p1980 (pole position identification technique) — check the configured procedure before forcing a new identification.
• p1982 (pole position identification selection) — toggling from 0 to 1 forces a new identification run.
• p0492 (square-wave encoder max. velocity difference per sampling cycle) — threshold against which the encoder speed change of fault value 1 (VECTOR) is measured.

Acknowledge the fault immediately after rectifying the cause. If the drive tripped with the OFF2 reaction, it must be restarted once the fault has been acknowledged. Where the wrong commutation angle came from pole position identification, force a new identification run (p1982 = 0 -> 1) before returning the drive to service.