6-2
Safe Torque Off
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames E & F
General Information
THIS EQUIPMENT IF USED INCORRECTLY IS POTENTIALLY DANGEROUS. THEREFORE
UNDER NO CIRCUMSTANCES SHOULD IT BE USED BEFORE THESE INSTRUCTIONS HAVE
BEEN READ AND UNDERSTOOD BY THE END USER WHO SHOULD BE APPROPRIATELY
QUALIFIED TO OPERATE THE EQUIPMENT.
This section provides general information about STO.
Two safety functions can be implemented with the 890: Safe Torque Off (STO) and Safe Stop 1 (SS1). In order
to meet all aspects of STO and SS1, an external safety control unit should be used.
To implement Safe Stop 1 (SS1), the external safety control unit causes the drive to decelerate to rest. Once at
rest, it invokes STO in the 890. Please refer to EN61800-5-2:2007 para 4.2.2.3 for the formal definitions.
It is the user’s responsibility to:
1)
Risk assess the machine.
2)
Design, implement and assess an appropriate solution for each application to meet all relevant safety
requirements.
Note: STO is an electronic inhibit intended for use during normal operation of the machine. It is not intended for
use during machine maintenance, repair, replacement or other similar activities. For these activities recognised
electrical power isolation devices and lock-off procedures should be used.
The 890 STO function is a factory-fitted and factory-tested feature. It is only compatible with firmware versions
3.5 and onwards. See the section “
Safety Warnings and Limitations
” on page 6-21.