Corrected from:
i950 servo inverter FW from V01.03.07.1252
Response of the new version:
After a short-circuit at the motor terminals U-V-W, the power section is disabled internally and an error message 0x2340 "CiA: Short-circuit (internal device)" is triggered. As long as the fault has not been reset, the state machine remains in the "Fault" state. Only after the error reset can the drive be enabled again.
What happens?
After a short circuit at the U-V-W motor terminals, the power section is internally inhibited, but no error message is triggered. The control electronics report no error and the state machine can be switched up to 'Operational'. However, the IGBTs remain inhibited and the motor is not energised, i.e. the required motion is not executed.
After removing the short circuit and restarting the inverter, enabling is possible, as expected.
When does this behaviour occur?
The behaviour occurs after a hard short circuit close to the U-V-W inverter terminals.
A monitoring function on the power section responds, but the status is not reported to the control electronics.
Which products are affected?
i950 servo inverter FW in design 8+9 (55-110kW)
Short-term measures:
After removing the cause of the short circuit
the inverter either has to be restarted
or another error has to be provoked (e.g. an encoder error by removing the encoder cable at the i950). When the error is reset, the monitoring function on the power section will be reset as well.
Evaluation/recommendations:
So far, the above-described behaviour has only been provoked/has only appeared in tests performed during the development.
Possible wiring errors during commissioning in the motor terminal board or insulation faults in cables or the motor winding typically do not lead to such a hard short circuit leading to the above-described behaviour.
