Vacon 100 INDUSTRIAL, Safety Manual

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STO and SS1 safety functions vacon • 15
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5
5. STO
AND
SS1
SAFETY FUNCTIONS
The safety functions of the OPTBJ board, such as the technical principle and data, wiring examples
and commissioning, will be described in this chapter.
NOTE! The use of STO, SS1 or other safety functions does not itself ensure safety. An overall risk
evaluation is required in order to make sure that the commissioned system is safe. Safety devices
like the OPTBJ board must be correctly incorporated into the entire system. The entire system
must be designed in compliance with all relevant standards within the field of industry.
Standards such as EN12100 Part 1, Part 2, & ISO 14121-1 provide methods for designing safe ma-
chinery and for carrying out a risk assessment.
5.1 Safe Torque Off (STO) principle
The STO safety function of the OPTBJ board allows the drive output to be disabled so that the drive
cannot generate torque in the motor shaft. For STO, the OPTBJ board has two separate, galvanically
isolated inputs STO1 and STO2.
NOTE! The STO inputs must be connected to +24V signal so that the drive can go to the enable state.
The STO safety function is achieved by disabling the drive modulation. The drive modulation is dis-
abled through two independent paths controlled by STO1 and STO2 so that a single fault in any of
the safety related parts will not lead to the loss of the safety function. This is done by disabling the
gate driver signal outputs to the driver electronics. The gate drive output signals control the IGBT
module. When gate drive output signals are disabled, the drive will not generate torque in the motor
shaft. See Figures 4 and 5.
CAUTION! The information in this manual provides guidance on the use of the
safety functions that OPTBJ option board provides together with Vacon 100 con-
trol board. This information is in compliance with accepted practice and regula-
tions at the time of writing. However, the end product/system designer is
responsible for ensuring that the system is safe and in compliance with relevant
regulations.
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