Safe Stop 1, Ss1; Basic Principle Of Operation; Monitoring Modes Of Ss1 - Siemens SINAMICS G120 Function Manual

2.4

Safe Stop 1, SS1

2.4.1

Basic principle of operation

The safety function SS1 monitors the
load speed and triggers the STO
function, if the load speed falls below a
limit value.
SS1 monitors the speed but not the
direction of rotation.
If you operate the motor with torque control, the inverter switches to the closed-loop speed
control mode when SS1 is selected.
2.4.2

Monitoring modes of SS1

You can select between two different monitoring modes of the SS1 function.
Figure 2-3
Your selection also influences the monitoring mode of the SLS function.
Braking ramp monitoring (p9306 = 1)
After selecting SS1, the inverter monitors braking with the SBR function (Safe Brake Ramp).
You define the braking ramp gradient during commissioning, i.e. it is independent of the
actual speed characteristic.
Select this monitoring mode if your motor, after selecting SS1, should always brake with the
same ramp (e.g. OFF3).
Safety Integrated Function Manual, SINAMICS G120 and G120C
Function Manual, 01/2011, FW 4.4, A5E03052391B AB
The two monitoring modes of the SS1 function
Description
2.4 Safe Stop 1, SS1
21