Pepperl+Fuchs KCD2-SON-Ex Series, Руководство пользователя

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Functional Safety KCD2-SON-Ex*(.R*)(.SP)
Planning
201
8-06
13
3.4 Characteristic Safety Values
The characteristic safety values like PFD, PFH, SFF, HFT and T
1
are taken from
the FMEDA report. Observe that PFD and T
1
are related to each other.
The function of the devices has to be checked within the proof test interval (T
1
).
Parameters Characteristic values
Assessment type and
documentation
Full assessment
Device type A
Mode of operation Low demand mode or high demand mode
HFT 0
SIL (hardware) 2
Safety function Inverted operation
1
1
The device can be used in 2 modes of operation, inverted operation and normal operation.
Normal operation
1

safe
2
2
"Annunciation failures" do not directly influence the safety function and are therefore not considered.
108 FIT 109 FIT

dd
3.3 FIT 3.3 FIT

du
3
26.0 FIT 24.2 FIT

total (safety function)
137 FIT 136 FIT
SFF 81 % 82 %
MTBF
3
3
acc. to SN29500. This value includes failures which are not part of the safety function/MTTR = 8 h.
The value is valid for one channel only.
328 years 328 years
PFH 2.60 x 10
-8
1/h 2.42 x 10
-8
1/h
PFD
avg
for T
1
= 1 year 1.14 x 10
-4
1.12 x 10
-4
PFD
avg
for T
1
= 2 years 2.28 x 10
-4
2.24 x 10
-4
PFD
avg
for T
1
= 5 years 5.69 x 10
-4
5.59 x 10
-4
Reaction time
4
4
Time between fault detection and fault reaction
< 20 ms
Table 3.3