Which products are affected?
9300 vector 0.37…90 kW SW V2.1
What happens?
The QSP ramp generator is loaded with a wrong sign which induces the drive to change briefly its direction of rotation. As a result, sudden changes in current or torque can occur or an external monitoring indicates a too large speed deviation.
When does the problem occur?
Under the following conditions if the quick stop (QSP) function is activated – e.g. due to tipp operation or when releasing a brake in a hoist application:
- QSP is activated within approx. 100 ms after the requested change of direction of rotation
- and the acceleration time (C0012) and deceleration time (C0013) are parameterised shorter than 1 s
Possible diagnostics?
Record the drive performance during QSP using the oscilloscope function (measuring signals MCTRL-NSET2 and MCTRL-NACT, MCTRL-QSP-OUT via ASW1).
Short-term measures/recommendations?
Use the input NSET-RFG-0 instead of the quick stop function to stop the drive. Regarding this, the configuration is to be changed as follows (see fig. 3):
- Disconnect the input MCTRL-QSP from the present source.
- Activate input NSET-RFG-0 with signal R/L/Q-QSP.
- If required, an additional deceleration ramp can be activated via C0103/1 when activating the input NSET-Ti*1 at the same time.
Note:
In contrast to the NSET-RFG-0 input, the MCTRL-QSP function does not only influence the speed setpoint but it affects also other functions (e.g. deactivation of the torque limitation). Therefore, this measure has always to be checked for being applicable at the drive.
Evaluation:
The consequences on the drive performance are usually minimal. Up to now this behaviour has only been recognised since in one case the setpoint speed and the actual speed have been compared with a very low tolerance for monitoring purposes.
