33 – Pvd3665_Gb_Ex_August 2022
1.2.3. Safe Torque Off function
The safe torque off function in accordance with the standards EN ISO 13849-1 : 2006 and
EN 61800-5-2 : 2006 is an electronic system set up on some drives certified by a notified
body. This is an unlocked input placed on the drive that must be connected (see the
commissioning and use manual of the drive).
The servomotors EX are equiped with a thermal protection which is checked by a safety
analysis and is a key element of the ATEX/IECEx safety. It is possible to connect this
protection to the unlocked input or through a safety system in accordance to the drive
specifications. This connection allows to maintain the drive power on, but disable the
motor after the activation of the thermal protection.
After an activation of this security device, the system must not restart automatically and
without a checking of the installation.
In all cases, the connection of this device must be checked and certified by a notified body.