CG Emotron OSTO 100, Instruction Manual

Page: 7 / 112

CG Drives & Automation 01-7513-11r0 General information 7
1. General information
The OSTO_100 option board for safety function Safe Torque Off (STO) is an
extension of the Emotron AC drive used for functional safety purposes to
achieve e.g. prevention of unexpected startup of motor (POUS) or Emergency
stop. This ensures the safety of both the operator and the machinery in
accordance with the Machine Directive.
During normal operation, safety equipment prevents people from accessing
hazardous areas. Sometimes work needs to be carried out in hazardous areas.
Function POUS may for instance be used in cases where tools connected to
motor shaft should be replaced or e.g. when cleaning the motor area (supply
voltage to the AC drive may remain enabled during this maintenance work).
The STO is a basic foundation which can be supplemented with additional
safety functions to also achieve e.g. safety function Safe Stop 1 (SS1-t). Working
principle of SS1-t is to utilize the AC drive to brake the motor down to
standstill before STO is activated. For safety function SS1-t, additional external
safety components are required (e.g. safety relay).
This manual contains technical data of the Emotron OSTO_100 option board
and explains the operation and connection of the board. The Safe Torque Off
function works according to the standards EN IEC 61800-5-2:2017, EN IEC
61508:2010, EN ISO 13849-1:2008 and EN IEC 62061:2005.
The AC drive control board in the Emotron AC drive provides pulse width
modulated (PWM) signals to the IGBT gate driver circuits on the Power board
via the safe torque off (STO) circuitry as depicted in Figure 1.
The STO will become activated if any of the two safety input channels STO1 or
STO2 become deactivated or upon abnormal electrical fault in The Emotron
OSTO_100 option. During normal operation condition both channels will be
deactivated simultaneously. Deactivation of only one channel can imply a fault
in e.g. wiring.