TIA Selection Tool, Safety Evaluation

Hello,

I'm testing Safety Evaluation  function in TIA Selection Tool (a replacement for Safety Evaluation Tool).

I created a simple configuration with an emergency stop pushbutton, safety PLC S7-1200 and third-party contactors to stop the motor. All subsystems (acquire, evaluate and react) have SIL CL 3 and very good PFHd, but the SRECS achieved SIL 1 only! SRECS PFHd achiever is 7.68E-09. 

SRECS SIL achieved should be SIL 3 in my opinion. Am I doing something wrong?

I see the CCF (Common Cause of Failure) for you ESTOP is 1 which is very low (CCF range is between 0-10 based on the CCF score 0-100). I guess that is the reason the ESTOP component doesn't achieve SIL3. hence the whole safety function.

Review your scoring of the CCF, and see if you can improve it. e.g. improve the EMC. 

Hello,

you haven't done anything wrong :-)

This is currently an error in the Safey Evaluation it will be fixed up to the September version.

Best regards

The SET-Team