Kromschroder FCU 500 - Safety-specific Characteristic Values

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
Tightness control 4.8 x 10
9 1/h
Large test volumes with reduced testing time 4.9 x 10
9
1/h
Emergency stop 4.9 x 10
9
1/h
Low air pressure protection 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
Low gas pressure protection 4.9 x 10
9
1/h
High gas pressure protection 4.9 x 10
9
1/h
Contactor feedback 4.8 x 10
9
1/h
STM/STL temperature module
*
5.8 x 10
9
1/h
* see page 126 (PFHD value for STM/STL temperature module
and thermocouple)
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