Siemens SINAMICS G120D Series User Manual

Advanced commissioning
7.8 Safe Torque Off (STO) safety function
7.8
Safe Torque Off (STO) safety function
These operating instructions describe the commissioning of the STO safety function when it
is controlled via a fail-safe digital input.
You will find a detailed description of all safety functions and control using PROFIsafe in the
Safety Integrated Function Manual, see Section Manuals for your converter (Page 316).
7.8.1
Function description
How does the STO safety function work?
The inverter with active STO prevents machine
components from inadvertently starting
.
Table 7- 30 The principle of operation of STO
Safe Torque Off (STO)
Standard inverter functions linked with STO
1. The inverter recognizes the selection of STO
via a safety-relevant input or via the PROFIsafe
safe communication.
---
2. The inverter prevents energy from being fed to
the motor. When STO is active, the motor does
not generate any torque.
If you use a motor holding brake, the inverter
closes the brake.
3. The inverter signals that "STO is active" via a
safety-relevant output or via the PROFIsafe
safe communication.
---
Figure 7-38 Functionality of STO when motor is rotating and at a standstill
If the motor is still rotating when STO is selected, then it coasts down to standstill.
Converter with control units CU240D-2
Operating Instructions, 04/2015, FW V4.7.3, A5E34262100B AB
201

Siemens SINAMICS G120D Series Specifications

General

Brand	Siemens
Model	SINAMICS G120D Series
Category	Media Converter
Language	English