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CONFIDENTIAL acc. to ISO 16016
Only valid as long as released in EDM or with a valid production documentation!
scale: 1:1
date: 2011-Jan-17
respons.
DP.HSU
approved
FS-0013PF-20C
Mannheim
FMEDA – Hardware Assessment
KF**-CRG2-**1.D
norm
sheet
8
of
10
template: FTM-0027_1
4. Results of the KF**-CRG2-**1.D
4.1. Results Relay Output
The FMEDA carried out on the Transmitter Supply Isolators KF**-CRG2-*** (relay output)
leads under the assumptions described to the following failure rates and SFF:
λ
sd
= 9,00E-09 1/h
λ
su
=
λ
su
+
λ
don’t care
+
λ
annunciation
= 1,67E-07 1/h + 1,77E-07 1/h + 3,36E-09 1/h = 3,47E-07 1/h
λ
dd
= 8,90E-08 1/h
λ
du
= 9,00E-08 1/h
λ
total
= 5,35E-07 1/h
λ
not part
= 3,88E-08 1/h
SFF = 83,18%
The PFD
AVG
was calculated for three different proof times.
Table 3: Relay output
T[Proof] = 1 year
T[Proof] = 2 years
T[Proof] = 5 years
PFD
AVG
= 3.94E-04 PFD
AVG
= 7.88E-04 PFD
AVG
= 1.97E-03
The boxes marked in yellow (
x x
) mean that the calculated PFD
AVG
values are within the
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 (
x x
) mean that the calculated PFD
AVG
values are
within the allowed range for SIL 2 according to the 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.
Released EDM checkout 23.02.2011