Siemens SINAMICS DCM - Page 51

Evaluating the safety functions according to EN ISO 13849 when using one switching device
9.3 Evaluation of "Respond"
Application document for functional safety STO, SS1 (ISO 13849-1)
Compact User Manual, 09/2016, A5E34871844AM
51
Calculation of the MTTF
D
for 3WL circuit breaker, channel 1
Parameter
Value
Reason
Definition
B10
B10 value 3WL circuit breaker
7.5 * 10
3
Manufacturers data SIEMENS AG
Percentage of dangerous failures
EMERGENCY STOP command
device
0.5 (50 %) Manufacturers data
d
op
average operating time in days per
year
365 days per year Assumption:
The device can be actuated every day
of the year
User
h
op
average operating time in hours
per day
24 hours per day
t
cycle
average time between the start of
two consecutive cycles of the com-
ponent
24 hours per cycle Assumption:
there is one day between actuating the
EMERGENCY STOP (testing the
EMERGENCY STOP)
Determination of the PL E-Stop for SINAMICS DCM channel 2
Parameter
Value
Reason
MTTF
D
SINAMICS DCM E-Stop
High MTTF
D
> 30 years (312 years)
DC
Low
DC = 67%
Measures against CCF
Fulfilled It is assumed that the user has taken the necessary
measures.