Ss1 With Speed Limit Activated Sbc, Sbc Before Sto - ABB FSO-21 User Manual

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SS1 with speed limit activated SBC, SBC before STO

In these examples, the SBC function is activated at a user-defined speed limit and
drive STO function after a user-defined delay (negative SBC delay). The reason to
use a negative SBC delay (parameter SBC.12) is to have the mechanical brake
closed just before the drive STO circuit is opened.
With time monitoring (SS1-t)
The operation of the SS1-t function with speed limit activated SBC, SBC before STO
is described in the time diagrams and tables below. For configuration, see section
How to configure SS1 with speed limit activated SBC, SBC before STO
Without an encoder
Motor speed
E
A
1
2
A SBC speed (parameter SBC.15): Speed limit below which the FSO activates the SBC
(brake).
B SS1-t delay for STO (parameter SS1.14): Time after which the FSO activates the STO
function regardless of the motor speed.
C SBC delay (parameter SBC.12): Time from the activation of the SBC function to the
moment when the FSO activates the drive STO function
D SBC time to zero (parameter SBC.13): Time from the SBC activation to the moment
when the safety function is completed and the SS1 completed indication (parameter
SS1.21) 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.
E Response time (depends on system configuration, see page 437)
B
SS1.14
- ->
C
SBC.12
3 3b
4
Safe torque off (STO)
SBC.13
D
6 7
5
.
Safety functions 85
on page 280.
Time
SS1 request
Drive STO state
& indication
SBC output
SS1 state &
indication
SS1 completed
indication