Safety Manual SIL HiD202*(SK), HiD2030(SK)
Planning
2
014-
05
11
HiD2029(SK), HiD2030(SK)
The characteristic safety values like PFD, PFH, SFF, HFT and T
proof
are taken
from the SIL report/FMEDA report. Please note, PFD and T
proof
are related to
each other.
The function of the devices has to be checked within the proof test interval
(T
proof
).
Parameters acc. to IEC 61508
Values
Assessment type
FMEDA report
Device type
A
Demand mode
Low Demand Mode or High Demand Mode
Safety function
2
Transfer of analog values
HFT
0
SIL
2
s
1
434 FIT
dd
0 FIT
du
95 FIT
no effect
2
167 FIT
not part
28.4 FIT
total (safety function)
528 FIT
SFF
82 %
MTBF
3
205 years
PFH
9.5 x 10
-8
1/h
PFD
avg
for T
proof
= 1 year
4.16 x 10
-4
PFD
avg
for T
proof
= 2 years
8.31 x 10
-4
PFD
avg
for T
proof
= 5 years
2.08 x 10
-3
1
"Not considered" failures are considered 50 % as dangerous undetected failures
du
and 50 % as safe
detected failures.
2
"No effect" failures are not influencing the safety functions and are therefore added to the
s
.
3
acc. to SN29500. This value includes failures which are not part of the safety function.
Table 2.4
