turck IM1-12-R Handbuch Seite 21

Table 2: Summary for MK13-R-Ex0 – Failure rates
λ
safe
288 FIT
Table 3: Summary for MK13-R-Ex0 – PFD
T[Proof] = 1 year
PFD = 4,80E-04
AVG
Table 4: Summary for IM1-***-R – Failure rates
λ
safe
299 FIT
Table 5: Summary for IM1-***-R – PFD
T[Proof] = 1 year
PFD = 4,80E-04
AVG
Table 6: Summary for IM1-***-T – Failure rates
λ
safe
267 FIT
Table 7: Summary for IM1-***-T – PFD
T[Proof] = 1 year
PFD = 3,72E-04
AVG
The boxes marked in yellow (
allowed range for SIL 2 according to table 2 of IEC 61508-1 but do not fulfill the requirement to
not claim more than 10% of this range, i.e. to be better than or equal to 1,00E-03. The boxes
marked in green (
SIL 2 according to table 2 of IEC 61508-1 and table 3.1 of ANSI/ISA–84.01–1996 and do fulfill
the requirement to not claim more than 10% of this range, i.e. to be better than or equal to
1,00E-03.
Because the Safe Failure Fraction (SFF) is above 60%, also the architectural constraints
requirements of table 2 of IEC 61508-2 for Type A subsystems with a Hardware Fault
Tolerance (HFT) of 0 are fulfilled.
A user of the Isolating Switching Amplifiers IM1-**(Ex)-* and MK13-R-Ex0 can utilize these
failure rates in a probabilistic model of a safety instrumented function (SIF) to determine
suitability in part for safety instrumented system (SIS) usage in a particular safety integrity level
(SIL). A full table of failure rates is presented in sections 5.1 to 5.3 along with all assumptions.
The failure rates are valid for the useful life of the Isolating Switching Amplifiers IM1-**(Ex)-*
and MK13-R-Ex0, which is estimated to be between 8 and 12 years (see Appendix 2).
It is important to realize that the "no effect" failures are included in the "safe undetected" failure
category according to IEC 61508. Note that these failures on its own will not affect system
reliability or safety, and should not be included in spurious trip calculations.
© exida.com GmbH
Stephan Aschenbrenner
more@turck.com • www.turck.com • 2015/04
Anhang – EXIDA-Report FMEDA Turck 04/07-14 R002
λ
dangerous
110 FIT
AVG
T[Proof] = 5 years
PFD = 2,40E-03
AVG
λ
dangerous
110 FIT
values
AVG
T[Proof] = 5 years
PFD = 2,40E-03
AVG
λ
dangerous
85 FIT
values
AVG
T[Proof] = 5 years
PFD = 1,86E-03
AVG
) mean that the calculated PFD
) mean that the calculated PFD
values
T[Proof] = 10 years
PFD
T[Proof] = 10 years
PFD
T[Proof] = 10 years
PFD
AVG
values are within the allowed range for
AVG
TURCK 04-07-14 R002 V3R0.doc; February 21, 2014
SFF
72%
= 4,79E-03
AVG
SFF
73%
= 4,79E-03
AVG
SFF
75%
= 3,71E-03
AVG
values are within the
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