Safety-Specific Characteristic Values - Honeywell Krom Schroder BCU 580 Technical Information

Technical data

16 .5 Safety-specific characteristic values

Suitable for Safety Integrity Level
Diagnostic coverage DC
Type of subsystem
Operating mode
Mean probability of dangerous failure
PFH
D
Mean time to dangerous failure
MTTF
d
Safe failure fraction SFF
Mean probability of dangerous failure PFH
individual safety functions
Valve proving system
Safety interlocks
Emergency stop with optional input
Air flow monitoring
Air flow monitoring with optional input
Flame control
Approaching position for ignition capacity with F1/IC 20 5.6 x 10
Approaching position for ignition capacity with F2/RBW
Approaching position for ignition capacity with F3
SIL 3 is only achieved in conjunction with actuators
IC 20 or RBW if a separate gas valve is used to limit the
pilot gas rate, see page 65 (Burner application), pa-
rameter 78 = 3.
BCU 580 · Edition 11.15l
Up to SIL 3
97.2 %
Type B to EN 61508-2:2010
High demand mode pursuant to EN
61508-4:2010
11.5 x 10 -9 1/h on BCU 580..F1
11.5 x 10 -9 1/h on BCU 580..F2
14.5 x 10 -9 1/h on BCU 580..F3
MTTF = 1/PFH
d D
99.4 %
of
D
5.5 x 10 -9
5.5 x 10 -9
5.4 x 10 -9
7.2 x 10 -9
7.1 x 10 -9
6.5 x 10 -9
-9
5.9 x 10 -9
5.3 x 10 -9
Relationship between the Performance Level (PL)
and the Safety Integrity Level (SIL)
PL
a
b
c
d
e
Pursuant to EN ISO 13849-1:2006, Table 4, the BCU
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 127 (Glossary).
1/h
For further information on SIL/PL, see www.k-sil.de
1/h
1/h
1/h
1/h
1/h
1/h
1/h
1/h
SIL
–
1
1
2
3
123