ABB FSO-12, User Manual

Page: 108 / 388

108 Safety functions
Step Description
1 The SLS request is received. The motor speed is above the SLS limit. The drive starts
to ramp down the motor speed. The SAR1 parameter
200.112 defines the deceleration
ramp slope until the speed reaches the SLS limit. The FSO starts the SAR1 ramp
monitoring (parameters
SARx.21 , SARx.22 ). SAR1 configuration defines the target and
monitoring limits for the deceleration ramp ( SARx.22 , 200.112 , SARx.02 ).
Note: If parameter 200.112 has value 0, the drive (drive parameter 23.23) defines the
ramp.
2 The drive trips on a fault, there is a drive power loss, or user stops the drive by coast
stop.
SAR1 monitoring of the FSO is on (parameter SLSx.05 configured as Monitoring active
and modoff delay time).
SLS Modoff delay time starts (parameters
SLSx.05 & SLSx.06 ).
As the modulation is lost, FSO's safe speed estimation is stopped and it starts to use
the last speed information that it had before the modulation was lost.
3 Modulation of the drive returns before the last valid speed information hits the SAR1
limit and before the modoff delay time has run out.
Deceleration continues as parametrized as long as the speed does not hit the SAR1
limits.
4 If modulation of the drive has not returned and the SLSx.06 Modoff delay time has run
out or the last valid speed reaches the SAR limit, FSO activates STO function and STO
indication (parameter STO.21 STO output). See section See section
Safe torque off
(STO) on page 55 for more information on how to configure the STO function.
5 The FSO starts the SLS monitoring when the motor speed is in the middle of the SLS
limit and the SLS trip limit (see also section
How to fine-tune when monitoring is started
on page 284 ), and stops the SAR1 monitoring. The SLS indication (parameters
SLSx.15, SLSx.24, SLSx.34 or SLSx.44) goes on.