Safety-Specific Characteristic Values - Honeywell BCU 460 Technical Information

Technical data

9 .3 Safety-specific characteristic values

In the case of ionization control,
suitable for Safety Integrity Level
Diagnostic coverage DC
Type of subsystem
Mode of operation
Mean probability of dangerous
failure PFH
D
Mean time to dangerous failure
MTTF
d
Safe failure fraction SFF
The specified values apply for the combination with
ionization electrode (sensor) and a unit of the BCU 400
series.
No characteristic values are available for flame control
with UVS sensor.
For flame control with UVD sensor, safety-specific
characteristic values are available for the Safety Integ-
rity Level SIL. Further information can be found in TI
UVD 1 at www.docuthek.com.
BCU 460, BCU 465 · Edition 03.16l
SIL 3
92.7%
Type B to EN 61508-2, 7.4.3.1.4
High demand mode pursuant to EN
61508-4, 3.5.12
1.92 x 10 -8 1/h
MTTF = 1 / PFH
d D
98.8%
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 89 (Glossary).
For further information on SIL/PL, see www.k-sil.de
SIL
–
1
1
2
3
86