Functional Safety K-LB-*.*, F*-LB-I, P-LB-*.*.*
Planning
20
21
-0
9
17
P-LB-1.A.*, P-LB-2.A.* (1oo1 structure)
Parameters
Characteristics
Assessment type
and documentation
FMEDA report
Device type
A
Mode of operation
Low demand mode or high demand mode
Safety function
1
1
The safe state of the surge protection barrier depend on the application.
Pass through the signal
HFT
0
SIL
2
2
The maximum safety integrity level of the safety loop in which the device might be used depends on the characteristics
of the whole saftey loop and the connected field devices in the application.
2 or 3
Signal type
1
AI
AO
DI
DO
Safe state
1
I
in
< 3.6 mA
Signal line
interrupted
I
out
< 3.6 mA
Signal line
interrupted
I
out
= 0 mA
U
out
= 0 V
Signal line
interrupted
I
out
= 0 mA
U
out
= 0 V
Signal line
interrupted
Safety loop fault
detection
3
3
This fault detection has to be provided by the safety loop architecture
(e. g. NAMUR signal
–
lead breakage and short circuit detection, current loop > 20 mA).
< 3.6 mA and
> 21 mA can be
detected
No fault detection
since < 3.6 mA is
safe state of the
safety loop
SC and LB detection
of the safety loop
No fault detection
sd
+
su
0 FIT
16.1 FIT
8.1 FIT
16.1 FIT
dd
16.1 FIT
0 FIT
8.0 FIT
0 FIT
du
0 FIT
0 FIT
0 FIT
0 FIT
no effect
41.1 FIT
41.1 FIT
41.1 FIT
41.1 FIT
not part
0 FIT
0 FIT
0 FIT
0 FIT
total (safety function)
16.1 FIT
16.1 FIT
16.1 FIT
16.1 FIT
MTBF
4
4
acc. to SN29500. This characteristic includes failures which are not part of the safety function/MTTR = 8 h.
2002 years (1-channel device), 1001 years (2-channel device)
PFH
0 1/h
0 1/h
0 1/h
0 1/h
PFD
avg
for
T
1
= 1 year
0
0
0
0
Table 3.6
