Which products are affected?
9300 vector 0.37…90 kW SW V7.1 and V7.2
9300 vector 110…400 kW SW V7.0
What happens?
After a parameter set transfer the drive controller indicates a PI trip (initialisation error). Sometimes the PI trip only occurs if an identification run has been executed after a parameter set transfer, the parameter set has been saved in a non-volatile mode and the mains has been connected.
When does the problem occur?
If a parameter set generated with a firmware version ≤ V6.3 is copied to a device with a firmware version ≥ V7.0 by means of the Global Drive Control or a keypad, a PI trip may occur immediately after the transfer. Up to now, the occurrence of the PI trip immediately after the transfer has only been detected if the keypad has been used for the transfer.
Sometimes the PI trip only occurs if an identification run has been executed after the parameter set transfer, the parameter set has been saved in a non-volatile mode and the mains has been connected. This behaviour has been detected after the transfer via keypad and Global Drive Control.
The PI trip is caused by the value entered under code C0912 (waiting time for recovery from OU). The setting of code C0912 depends on the motor data and results from the double rotor time constant TR which is calculated from C0082 and C0092 as shown in the following formula. The automatic calculation is executed during the online parameter setting process.
C0912[ms] = TR[ms] * 2 = 2 * Stator inductance C0092 in [mH] / Rotor resistance C0082 in [Ohm]
The automatic setting for C0912 can be changed manually by factor 0.5...2. The attempt to enter values which are outside this range is rejected.
Unfortunately, a value which is not within the range mentioned above, is erroneously entered under code C0912 if parameter sets are transferred or an identification run has been made. Thus the PI trip is caused.
Possible diagnostics?
While the PI trip is pending in the device, codes C0082, C0092 and C0912 are to be read out. By means of the formula for code C0912 it can be traced if the value for code C0912 is outside the range allowed.
Short-term measures/recommendations?
If the value under C0082 (rotor resistance) or C0092 (stator inductance) is acknowledged, C0912 is recalculated.
Procedure:
The procedure described in the following is to be applied separately for all parameter sets used.
• Load the parameter set required into the RAM (C0002)
• In the keypad: Call up C0006 and confirm the value with 'Shift+Prg'
• Or in GDC: Call up C0006 and confirm the value with 'ok' or 'Acceptance'
• In order to achieve that the changed value under C0095 is indicated in GDC the value must sometimes be read back from the drive controller at first (F6 = Read the marked parameter from the drive or F7 = Transmit parameter set from drive to PC)
• The PI trip can now be reset
• Save the parameter set in the non-volatile mode (C0003)
Note: The recalculation of code C0132 (minimum time for controller inhibit if the flying restart circuit is activated) is also triggered by acknowledging C0082 or C0092. Code C0132 is available as of firmware version V7.0
Evaluation:
The behaviour may especially occur if during a service mission a device is to be replaced or if during the commissioning of series applications an already existent parameter set is used. The drive cannot be enabled if a PI trip is pending. The occurrence of the behaviour depends on the constellation of the parameters C0088 (rated motor current), C0082 (motor rotor resistance) and C0092 (motor stator resistance) to each other. By looking at the original parameter set the user cannot find out if the behaviour will occur when a parameter set is transferred.
