Rockwell Automation 21G PowerFlex 750-Series AC Drives Reference Manual - Manual (Page 16)

16 Rockwell Automation Publication 750-RM001F-EN-P - February 2012
Chapter 1 Safety Concept
Important Safety Considerations
The system user is responsible for:
• the setup, safety rating, and validation of any sensors or actuators
connected to the system.
• completing a system-level risk assessment and reassessing the system any
time a change is made.
• certification of the system to the desired safety performance level.
• project management and proof testing.
• programming the application software and the safety option
configurations in accordance with the information in this manual.
• access control to the system, including password handling.
• analyzing all configuration settings and choosing the proper setting to
achieve the required safety rating.
Safety Category 4 Performance Definition
To achieve Safety Category 4 according to ISO 13849-1:2006, the safety-related
parts have to be designed such that:
• the safety-related parts of machine control systems and/or their protective
equipment, as well as their components, shall be designed, constructed,
selected, assembled, and combined in accordance with relevant standards
so that they can withstand expected conditions.
• basic safety principles shall be applied.
• a single fault in any of its parts does not lead to a loss of safety function.
• a single fault is detected at or before the next demand of the safety
function, or, if this detection is not possible, then an accumulation of faults
shall not lead to a loss of the safety function.
• the average diagnostic coverage of the safety-related parts of the control
system shall be high, including the accumulation of faults.
• the mean time to dangerous failure of each of the redundant channels shall
be high.
• measures against common cause failure shall be applied.
IMPORTANT When applying functional safety, restrict access to qualified, authorized
personnel who are trained and experienced.
ATTENTION: When designing your system, consider how personnel will exit
the machine if the door locks while they are in the machine. Additional
safeguarding devices may be required for your specific application.