FCU 500, FCU 505 · Edition 02.17
141
Technical data
18 .6 Safety-specific characteristic values
Suitable for Safety Integrity Level
Up to SIL 3
Diagnostic coverage DC
98.2%
Type of subsystem
Type B to EN 61508-2, 7.4.3.1.4
Operating mode
High demand mode pursuant to
EN 61508-4, 3.5.12
Mean probability of dangerous failure
PFH
D
15.5 x 10
-9
1/h
Mean time to dangerous failure MTTF
d
MTTF
d
= 1/PFH
D
Safe failure fraction SFF
99.6%
Mean probability of dangerous failure PFH
D
of
individual safety functions
4.8 x 10
-9 1/h
Large test volumes with reduced testing time
4.9 x 10
-9
1/h
4.9 x 10
-9
1/h
4.9 x 10
-9
1/h
Ready feedback
5.9 x 10
-9
1/h
IC 20 ignition position feedback
6.7 x 10
-9
1/h
RBW Low position feedback
6.7 x 10
-9
1/h
4.9 x 10
-9
1/h
4.9 x 10
-9
1/h
4.8 x 10
-9
1/h
5.8 x 10
-9
1/h
* see page 126 (PFHD value for STM/STL temperature module
SIL 3 is not achieved in conjunction with actuators
IC 20 or RBW because there are no PFH
D
values for the
actuators.
Relationship between the Performance Level (PL)
and the Safety Integrity Level (SIL)
PL
SIL
a
–
b
1
c
1
d
2
e
3
Pursuant to EN ISO 13849-1:2006, Table 4,
the FCU can be used up to PL e.
Max. service life under operating conditions:
20 years after date of production.
For a glossary of terms, see page 145 (Glossary).
For further information on SIL/PL, see www.k-sil.de