Rockwell Automation 2099-BMxx-S Kinetix Safe Torque-off Feature Safety Reference Manual - Manual (Page 11)

Rockwell Automation Publication GMC-RM002F-EN-P - June 2013 11
Safety Concept and Troubleshooting Chapter 1
Low Voltage Directive
These units are tested to meet Council Directive 2006/95/EC Low Voltage
Directive. The EN 60204-1 Safety of Machinery-Electrical Equipment of
Machines, Part 1-Specification for General Requirements standard applies in
whole or in part. Additionally, the standard EN 61800-5-1 Electronic
Equipment for use in Power Installations apply in whole or in part.
Refer to the Kinetix Servo Drives Specifications Technical Data, publication
GMC-TD003 , for environmental and mechanical specifications.
Description of Operation The safe torque-off feature provides a method, with sufficiently low probability
of failure, to force the power-transistor control signals to a disabled state. When
disabled, or any time power is removed from the safety enable inputs, all of the
drive output-power transistors are released from the On-state. This results in a
condition where the drive is coasting (stop category 0). Disabling the power
transistor output does not provide mechanical isolation of the electrical output,
which may be required for some applications.
Under normal operation, the safe torque-off inputs are energized. If either of the
safety-enable inputs are de-energized, then all of the output power transistors will
turn off. The safe torque-off response time is less than 25 ms.
PFD and PFH Specifications Safety-related systems can be classified as operating in either a Low Demand
mode, or in a High Demand/Continuous mode:
• Low Demand mode: where the frequency of demands for operation made
on a safety-related system is no greater than one per year or no greater than
twice the proof-test frequency.
• High Demand/Continuous mode: where the frequency of demands for
operation made on a safety-related system is greater than once per year.
The SIL value for a low demand safety-related system is directly related to order-
of-magnitude ranges of its average probability of failure to satisfactorily perform
its safety function on demand or, simply, average probability of failure on demand
(PFD). The SIL value for a High Demand/Continuous mode safety-related
system is directly related to the probability of a dangerous failure occurring per
hour (PFH).
ATTENTION: Permanent magnet motors can, in the event of two simultaneous
faults in the IGBT circuit, result in a rotation of up to 180 electrical degrees.