Corrected from:
- i700 servo inverter V01.07.05.10577
Response of the new version:
Brake application in the case of overvoltage (OU) is ensured even in the event of a short-time overvoltage.
What happens?
The inverter is inhibited by the overvoltage monitoring on the hardware side, but the controller remains in the 'Operation enabled' state and the brake remains released. In fact, the brake should be applied because the controller can no longer generate any torque.
When does this behaviour occur?
This situation may occur if the overvoltage event was very short, in the range of < 1ms.
In this case, the inverter will be inhibited on the hardware side and the device will thus be protected if an overvoltage occurs, but the 'information' will not be reported to the control processor. As a result, the control remains in the 'Operation enabled' state and the brake remains released.
Which products are affected?
- i700 servo inverter ≤ V01.06.03.9953
Short-term measures:
Take applicative measures to ensure that the brake is applied.
Evaluation/recommendations:
In the case of overvoltage events during normal operation, e.g. during braking phases or when lowering hoists, the dimensioning of the brake chopper/brake resistor should be checked, if necessary. Possibly, the peak braking power will not be sufficient (resistor too large) to dissipate the braking energy fast enough.
