Siemens SINAMICS DCM - Evaluation of Two Power Contactors; Result Respond When Using Two 3 WL Circuit Breakers

Evaluation of the safety function according to EN 62061
11.3 Evaluation of "Respond"
Application document for functional safety STO, SS1 (ISO 13849-1)
Compact User Manual, 09/2016, A5E34871844AM
67
11.3.1.2
Evaluation of two power contactors
Result
Result
Reason
SILCL
3
Hardware fault tolerance HFT=1
PFH
D
7.3 E-09 2-channel architecture, switch off of different voltage
sources
Values to calculate the PFH
D
Parameter
Value
Reason
Definition
B10
B10 value power contactor
1 *10
6
Manufacturers data SIEMENS AG
Percentage of dangerous
failures
power contactor
0.73 (73 %) Manufacturers data
T1
service life
175200 h Expected service life, 20 years
C
Number of times that the
power contactor is ener-
gized
1 / 24 h Annahme:
The device is energized once a day
The device can be energized every day of the
year
User
T2
Diagnostic test interval
24 h It is actuated once a day.
A defective contact is detected.
CCF factor (β)
susceptibility to common-
cause failures
0.1 (10 %) When installed according to EN 62061, this can
assumed to be a "conservative value"
DC
Diagnostic Coverage
0.99 (99 %) Direct monitoring using mirror contacts
11.3.2
Result "Respond" when using two 3WL circuit breakers
Result
Reason
SILCL
SIL claim limit
2
The tables with the values to be determined are listed in
Section 11.3.1.1.
PFH
D
Average probability of a dangerous
failure per hour
3.21 E-08