Assessment Of Functional Safety According To Iec 61508 - Siemens SIPROTEC 5 7UM85 Manual

5 Assessment of Functional Safety According to
IEC 61508
The 7UM85 devices have been subjected to an assessment of functional safety according to the standard
IEC 61508.
The following table shows the assessment results of the 8 variants for the 7UM85 device. All the assessment
values are based on an ambient temperature of 40 °C (104 °F) according to the standard IEC 60255-1.
NOTE
i
i
If you need assessment values which are based on other ambient temperatures, contact the Customer
Support Center. You can find more information of the Customer Support Center in
Item
Diagnostic coverage
Safe fail fraction (SFF)
Undetected, dangerous failure
rate (λ )
DU
Detected, dangerous failure
rate (λ )
DD
Undetected and detected safe
failure rate (λ and λ )
SU SD
Probability of failure on
demand (PFD)
Safety integrity level (SIL)
Hardware architecture
Hardware failure tolerance
Type of subsystem
Proof test interval
Mean time to restore
Base module: CP300_2 + PS201 + IO202
Variant 1: Base module + IO205 + IO206
Variant 2: Base module + IO205 + IO207
Variant 3: Base module + IO231 + IO206
Variant 4: Base module + IO207 + IO207 + IO207
Variant 5: Base module + IO207 + IO207 + IO201
Variant 6: Base module + IO207 + IO207
Variant 7: Base module + IO207 + IO206
Variant 8: Base module + IO201 + IO205
SIPROTEC 5, Additional Information on the Protection of Explosion-Proof Motors with Type of Protection Increased Safety e,
Manual
C53000-H5050-C078-1, Edition 03.2019
Variant 1 Variant 2 Variant 3 Variant 4 Variant 5 Variant 6 Variant 7 Variant 8
87 % 85 % 89 %
94 % 93 % 94 %
3866 4856 3513
25 783 27 741 29 336
29 883 32 646 30 990
1.7 ⋅ 10 -2 2.1 ⋅ 10 -2 1.6 ⋅ 10
82 % 82 % 82 %
91 % 91 % 92 %
6858 6285 5212
31 007 29 206 24 492
37 836 36 091 31 651
-2 3.0 ⋅ 10 -2 2.7 ⋅ 10 -2 2.3 ⋅ 10
1
1oo1
0
B
1 year
8 h
Support, Page 5.
84 % 86 %
92 % 93 %
4222 4283
22 535 25 940
28 888 30 901
-2 1.9 ⋅ 10 -2 1.9 ⋅ 10 -2
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