Sls With Speed Above The Monitored Speed - Time Monitoring - ABB ACS880 User Manual

18 Option description
1. The user or a PLC de-energizes the applicable digital inputs of the FSO module. This
activates the SLS request.
2. After the safety function response time (A), the FSO module starts to monitor the motor
speed. The FSO module energizes the digital output that indicates the SLS status.
While the monitoring is active, the inverter unit limits the motor speed so that it stays
at or below the SLS1 limit positive. The FSO module monitors the actual motor speed.
(2b) If the motor speed goes above the SLS1 trip limit positive (C), the FSO module
activates the SSE function, starts a counter for time (D) and the motor coasts to a stop
(in this case, the SSE function is configured as Immediate STO, refer to section
Parameters for the SSE function (page
3. The user or a PLC energizes the applicable digital inputs of the FSO module. This
deactivates the SLS request. The FSO module acknowledges the SLS1 function
automatically. This is set by an FSO parameter (SLSx.02), and no external
acknowledgement input is used. The FSO module stops SLS monitoring and
de-energizes the SLS indication signal.
(3b) Time (D) has elapsed. If the FSO module activated the SSE function at 2b, the
FSO module activates the SLS indication and the STO acknowledgement becomes
allowed now. The user must reset the inverter unit if the STO indication parameter
(FSOGEN.62 or 31.22) is set so that a fault is generated.

SLS with speed above the monitored speed - time monitoring

This time scheme diagram illustrates the operation of the SLS function with time monitoring.
The motor speed is above the monitored speed when the SLS function is activated.
Motor speed
B
A
C
1 2
A Safety function response time
B SLS time delay (parameter SLSx.04): When time B has elapsed from the start of the counter (step
1 below), the FSO module starts SLS monitoring (if not already started).
C SLS1 limit positive (parameter 200.23)
D SLS1 trip limit positive (parameter SLSx.14)
SLSx.04
3 3b
36)).
D
4
Time
5
SLS request
SLS status &
indication