Eliminated from:
Inverter Drives 8400 StateLine, HighLine and TopLine from firmware version 12.00.00.00
Behaviour of the new version?
If a synchronous machine is detected from the motor parameters, the short-circuit test after controller enable is dispensed with. The short-circuit monitoring itself is implemented in the hardware and is not affected by the change. An actual short circuit, however, might not be detected immediately after controller enable.
Which products are affected?
Inverter Drives 8400 StateLine, HighLine and TopLine with a firmware version lower than 12.00.00.00
What happens?
Directly after controller enable, the OC1 monitoring function (short circuit of power section) responds although no short circuit is pending.
When does the problem occur?
During the operation of small synchronous machines with a very low leakage field inductance.
During the short circuit measurement, the current increases so quickly that the monitoring function attributes this to a short circuit.
Diagnostics options?
If, with deactivation of the earth fault monitoring (C0602 = 0), a short circuit error can no longer be observed directly after controller enable, the behaviour described is observable.
Short-term measures/recommendations?
By selecting the 'No reaction' response of the earth fault monitoring (C0602 = 0), a short circuit test after controller enable is not carried out anymore. Like this, the undesired response of the short circuit monitoring function can be avoided.
Evaluation:
When the earth fault monitoring is activated, reliable operation of the inverter with a corresponding synchronous machine is not possible. An actual short circuit is detected nevertheless.
