Siemens SINAMICS G120X, Руководство по эксплуатации

Страница: 299 / 1148

The STO safety function conforms to IEC/EN 61800-5-2.
The STO function is defined in IEC/EN 61800-5-2:
"[…] [The converter] does not supply the motor with power that can generate a torque (or for a
linear motor, a force)".
Precondition
The machine manufacturer has already performed a risk assessment, e.g. in compliance with
EN ISO 1050, "Safety of machinery - Principles of risk assessment".
Function description
Safe Torque Off (STO) Standard converter functions linked with STO
1. The converter detects that STO has been selec‐
ted via the failsafe digital input.
---
2. The converter prevents the energy supply to the
motor.
If you use a motor holding brake, the converter
closes the motor holding brake.
If you use a line contactor, the converter opens
the line contactor.
6SHHG
6HOHFW672
672LVDFWLYH
6HOHFW672
672LVDFWLYH
6SHHG
W
W
W
W
W
W
% $
Figure 6-28 Functionality of STO when the motor is at standstill (A) and rotating (B)
(A): When selecting STO, if the motor is already stationary (zero speed), then STO prevents the
motor from starting.
(B): If the motor is still rotating (B) when STO is selected, it coasts down to standstill.
Example
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.
When STO is active, the converter can no longer electrically brake the motor, so that STO does
not shorten the time that it takes for machine components to coast down to zero speed.
Application example Possible solution
When the EMERGENCY STOP button
is pressed, it is not permissible for a sta‐
tionary motor to inadvertently acceler‐
ate.
● Connect the EMERGENCY STOP pushbutton with the
failsafe converter digital input.
● Select STO via the failsafe digital input.
Advanced commissioning
6.3 Drive control
SINAMICS G120X converter
Operating Instructions, 06/2019, FW V1.01, A5E44751209B AC
297