ABB FSO-21 - SLS Reaction When Modulation Is Lost During Deceleration Ramp, with Ramp Monitoring

Safety functions 147
 SLS reaction when modulation is lost during deceleration ramp,
with ramp monitoring
If SLS function is activated when motor speed is above the SLS trip limit, FSO will
force the drive to decelerate to SLS limit. If the drive stops modulation during this
deceleration ramp, user can pre-select the reaction of the SLS function (parameter
SLSx.05) from the following:
• Modoff delay time
• Monitoring active
• Monitoring active and modoff delay time
• Monitoring and modoff delay time disabled.
SLS reaction if modulation is lost with Modoff delay time
The operation of the SLS function in case the modulation of the drive is lost during the
deceleration ramp with Modoff delay time selected (parameter SLSx.05 is set to
Modoff delay time) is described in the time diagram and table below. For
configuration, see section How to configure SLS function behavior when drive
modulation is lost on page 376.
A SAR1 ramp monitoring
B Actual motor speed (coasting after modoff)
C SLS trip limit
DSLS limit
SLS indication
STO.14 delay
Motor speed
Time
1 3 42
C
A
A
D
B
Drive modulation
SLS request
SAR1 monitoring
SLSx.06 Modoff
delay time monitoring
STO active