Siemens Simovert Masterdrives Compendium page 68

Configuration and Connection Examples
Measures against
common cause
failure (CCF) of the
safety function
Check of the PFH
value of the safety
functions as a whole
2.4.6.2 Supplementary safety function Emergency Stop
Assumption
2-40
In accordance with ISO 13849-1, a minimum of 65 points are required
for SRP/CS from category 2.
The observations stated in subsection 2.4.5.2 "Measures against
common cause failure (CCF) of the safety function" apply.
A sufficient total of 65 points is thus achieved.
Parameter PFH value
ACQUIRE 2.47 x 10
EVALUATE 2.62 x 10
4.29 x 10
REACT
Total 7.02 x 10
The requirements regarding PL d with Category 3 for the
protective door safety function are thus fulfilled.
The drive must be switched off safely if the Emergency Stop button is
actuated.
The Emergency Stop button is actuated 1x per month.
This safety function can be assessed according to the same principles
described in subsection 2.4.5.1 "Emergency Stop on a converter →
STO".
The safety switching device –A2 plays no role in the Emergency Stop
function and need not therefore be included in the calculation for this
supplementary protective measure.
The switching cycles of –K1 caused by actuation of the door have no
relevant influence on the calculation for this supplementary safety
function.
PL Comment
-8
/ h e Position switches –S4 and –S5
-9
/ h d Safety switching devices –A2
-8
/ h Switching elements –K1, -K2 and
d –K3
-8
/ h d < 1x10
6SE7087-6QX70 (Version AM)
Compendium Motion Control
12.2010
-6
/ h
Siemens AG
SIMOVERT MASTERDRIVES