Prerequisite For Sto Use - Siemens SINAMICS G120D Operating Instructions Manual

Application examples for the STO function
The STO function is suitable for applications where the motor is already at a standstill or will
come to a standstill in a short, safe period of time through friction. STO does not shorten the
run-on of machine components with high inertia.
Examples
When the Emergency Stop button is pressed, a
stationary motor should not unintentionally start.
A central emergency stop button must prevent the
unintentional acceleration of several motors that
are at a standstill.
6.8.2

Prerequisite for STO use

In order to use the STO safety function, the machine manufacturer should have already
performed a risk assessment, e.g. in compliance with EN ISO 1050, "Safety of machinery -
Principles of risk assessment". The risk assessment must confirm that the inverter is
permitted for use in accordance with SIL 2 or PL d.
Converter with control units CU240D-2
Operating Instructions, 07/2016, FW V4.7 SP6, A5E34262100B AD
Advanced commissioning
6.8 Safe Torque Off (STO) safety function
Possible solution
Wire the Emergency Stop button to a fail-
•
safe input of the inverter.
Select STO via the fail-safe input.
•
Evaluate the Emergency Stop button in a
•
central control.
Select STO via PROFIsafe.
•
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