Functional Safety KFD2-SH-Ex1(.T)(.OP), KHA6-SH-Ex1
Planning
20
17-
04
15
KFD2-SH-Ex1.T(.OP)
The characteristic safety values like PFD, PFH, SFF, HFT and T
1
are taken from
the FMEDA report and the assessment documentation created by the issuer.
Please note, 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
).
The safety values MTTF
d
, DC
d
, Category and PL for the machinery directive are
taken from the assessment report and certificate.
Parameters acc. to IEC 61508
Characteristic values
Assessment type and
documentation
FMEDA, proven-in-use assessment, certificate
Device type
A
Mode of operation
Low Demand Mode or High Demand Mode
HFT
0
SIL
3 (proven-in-use)
2 (proven-in-use)
Safety function
Output I is de-energized when
input in low state
Output II is de-energized when
input in low state
s
181 FIT
194 FIT
du
1.4 FIT
51.6 FIT
dd
38.4 FIT
38.4 FIT
no effect
1
1
"Annunciation failures" are not directly influencing the safety functions and are therefore added to the
no effect
value.
195 FIT
130 FIT
total (safety function)
218 FIT
282 FIT
SFF
99.4 %
81 %
MTBF
2
2
acc. to SN29500. This value is calculated with the failure rates of the device components which are part of the
safety function of the device.
275 years
276 years
MTTF
d
2860 years
–
DC
d
96.5 % (medium)
–
B10
d
–
–
Category (ISO 13849-1)
3
–
PL
d
–
PFH
1.38 x 10
-9
1/h
5.16 x 10
-8
1/h
PFD
avg
for T
1
= 1 year
6.04 x 10
-6
2.26 x 10
-4
PFD
avg
for T
1
= 2 years
1.21 x 10
-6
4.52 x 10
-4
PFD
avg
for T
1
= 5 years
3.02 x 10
-5
1.13 x 10
-3
Reaction time
3
3
Time between fault detection and fault reaction.
< 30 ms
< 30 ms
Table 3.3