ABB FSO-21 - Page 136

136 Safety functions
With ramp monitoring
The operation of the SSE with speed limit activated SBC, SBC before STO and ramp
monitoring is described in the time diagrams and tables below. For configuration, see
section How to configure SSE with speed limit activated SBC, SBC before STO on
page 360.
With a safe speed estimate
A SBC speed (parameter SBC.15): Speed limit below which the FSO activates the SBC
(brake) while ramping. The SAR0 ramp monitoring is stopped.
B SBC delay (parameter SBC.12): Time from the activation of the SBC function to the
moment when the FSO activates the drive STO function
.
C SBC time to zero (parameter SBC.13): Time from the SBC activation to the moment
when the safety function is completed and the SSE completed indication (parameter
SSE.22) goes on. The acknowledgment becomes allowed. You must set this to the
estimated time in which the motor brakes to a stop from the maximum speed.
D Response time (depends on system configuration, see page 532)
Ramp monitoring limits
Drive STO state
& indication
SSE request
Motor speed
Time
SSE state &
indication
1
7
2 5
SBC output
3
A
D
SSE completed
indication
SAR0
monitoring
3b
B
SBC.12
C
SBC.13
4 6
- -> Safe torque off (STO)