Siemens SINAMICS DCM - Evaluation of Detect

Evaluation of the safety function according to EN 62061
11.1 Evaluation of "Detect"
Application document for functional safety STO, SS1 (ISO 13849-1)
64 Compact User Manual, 09/2016, A5E34871844AM
11.1
Evaluation of "Detect"
Result
Result
Reason
SILCL
SIL claim limit
3 Safe failure fraction ≥ 99 %
Hardware fault tolerance HFT=1
PFH
D
Average probability of a dangerous
failure per hour
8.33 E-10 2-channel architecture with identical partial systems
Values to calculate the PFH
D
Parameter
Value
Reason
Definition
B10
B10 value EMERGENCY STOP
command device
1 * 10
5
Manufacturers data SIEMENS AG
Percentage of dangerous failures
EMERGENCY STOP command
device
0.2 (20 %) Manufacturers data
T1
service life
175200 h Expected service life, 20 years
C
Number of times that the
EMERGENCY STOP command
device is actuated
1 / 24 h Assumption:
The device is actuated once a day
The device can be actuated every
day of the year
User
T2
Diagnostic test interval
24 h It is actuated once per day. A de-
fective 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 %)
Cross comparison in the switching
device