endix C - IEC 61508 Failure
Certified SIL 2 Capable
IEC 61508:2000 Parts 1, 2,
3
Using reliability data extracted from the exida Electrical and Mechanical
Component Reliability Handbook the following failure rates resulted from
the FDS301 FMEDA.
The useful lifetime of components contributing to dangerous undetected failure is approximately
50 years (Ref: Report No.: MP 08/02-03 R004 V1 R2).
Safe Failure Fraction (SFF): 91.2%
Proo
Proof testing should be carried out on a yearly basis, showing a probability of failure on demand
average (PFD
AVG
) of 3.38E-04.
This document is strictly private and confidential, reproduction without Micropack approval is prohibited. © Micropack Engineering Ltd, 2015
Step Action
1 By-pass /inhibit the safety function and take appropriate action to avoid a false trip.
2 Clean window of detector using a soft cloth and detergent.
3 Perform a test of the FDS301 using the FS301.
4 Remove the by-pass/inhibit and restore normal operation.
Failure Category Failure Rate (FIT)
Fail Safe Undetected
10.3
Fail Dangerous Detected
638.0
Fail Detected (detected by internal diagnostics)
547.4
Fail High (detected by logic solver)
19.6
Fail Low (detected by logic solver)
71.0
Fail Dangerous Undetected
76.0
Annunciation Undetected
21.1
FDS301 Flame Detector FDS301 Safety and Technical Manual
35
Ref: 2200.5009 Rev: 2.3 ECN 4434
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