Configuration 395
negative SMS trip limit is set close to zero speed, there is an increased possibility that
the error spike could cause an unnecessary trip.
This example also applies to:
• trip limit hits in the SLS1...4 and Variable SLS functions when the SLSx mute
times are disabled with parameter FSOGEN.38
all trip limit hit situations regardless of parameters FSOGEN.38 and FSOGEN.39 if
encoder is used.
Example 2: SLS safe speed estimate trip limit hit situation
Note: This example is for more complex systems which cannot be properly
configured with general transient mute time.
This example covers safe speed estimate trip limit situations with acceleration of an
induction motor. It is possible that safe speed estimate goes above the SLS trip limit
for limited time when an induction machine is accelerated with high load inertia. In
- - - Actual speed
Safe speed estimate
SMS trip limits
1 Error spike caused by the starting of the synchronous motor, spike duration 50 ms.
FSOGEN.31 is set longer that the error spike and the SSE is not activated.
2 Safe speed estimate exceeds the SMS trip limit
3 FSOGEN.31 Transient mute time has elapsed. SSE is activated.
To Next Page
Loading...
