F07907 — Internal armature short-circuit: Motor terminals are not at zero potential after pulse

F07907 appears when the function "Internal voltage protection" (p1231 = 3) has been activated. It is not a defect report: the manual treats the entry as a note for the user, addressed to the Power Module. With the internal voltage protection active, all of the motor terminals sit at half of the DC link voltage after pulse suppression, whereas without the function they would be at zero potential — that difference is what the message title refers to. The cause text is identical in the manuals for G130, G150, S120 and S150, so the conditions below apply to all of these families equally.

• The function "Internal voltage protection" was activated by setting p1231 = 3. No other cause is given: everything the manual adds is a condition that must be observed while the function is active, not a further fault.

1. Only motors that are short-circuit proof may be used while the internal voltage protection is active: p0320 must be less than p0323.
2. Check the current coverage. The manual requires verbatim: the Motor Module must be able to continually conduct 180% short-circuit current (r0331) of the motor (r0289).
3. Remember that the internal voltage protection cannot be interrupted due to a fault response. If an overcurrent condition occurs while it is active, this can destroy the Motor Module and/or the motor.
4. Check bit 10 of r0192. If the Motor Module does not support the autonomous internal voltage protection (r0192.10 = 0), an external 24 V power supply (UPS) must be used for the components to ensure safe, reliable functioning when the line supply fails. If it does support it (r0192.10 = 1), the 24 V power supply for the components must be provided through a Control Supply Module.
5. While the internal voltage protection is active, the motor must not be driven by the load for a longer period of time — for example as a result of loads that move the motor or another coupled motor.

• p1231 — setting it to 3 activates the internal voltage protection and is what raises this entry; the parameter configures the armature short-circuit / DC braking function (ASC/DCBRK).
• p0320, p0323 — compare the two for the short-circuit-proof condition: the motor short-circuit current p0320 must be less than the maximum motor current p0323.
• r0331 — actual motor short-circuit current; the Motor Module must be able to continually conduct 180% of this value.
• r0289 — maximum power unit output current; read it on the Motor Module side when verifying the 180% short-circuit current requirement above.
• r0192 — check bit 10 to see whether the Motor Module supports the autonomous internal voltage protection (0 = not supported, 1 = supported).

There is no remedy and none is needed — the manual classifies the entry as a note for the user. The drive triggers no automatic response; acknowledge the message (for example from the operator panel or the commissioning tool) and it is cleared. If you want to work through the conditions the note lists, use the checklist above, because they protect the Motor Module and the motor while the internal voltage protection is running.