MEDC XB15 Manuel d'utilisation
Page 6
02/15
© MEDC 2015
Under fault conditions the failure mode of the Beacon is a failure to provide a spherical visual warning
light. For the failure rate associated with this failure mode please refer to the table below.
Assessment of Functional Safety
This beacon is intended for use in a safety system conforming to the requirements of IEC61508.
Sira Test & certification Ltd has conducted a Failure Modes Effect and Diagnostic Analysis (FMEDA) of the DC
version of XB15 Xenon beacon against the requirements of IEC 61508-2 using a Proof Test Interval of 8760hrs.
The DC version of the beacon was considered to be the worst case.
The results are shown below and are based on Route 1H .
The beacon is classed as a Type B device
Proven in Use Summary Tab
Conditions of Safe use
The following conditions apply to the installation, operation and maintenance of the assessed
equipment. Failure to observe these may compromise the safety integrity of the assessed equipment:
1. The user shall comply with the requirements given in the manufacturer’s user documentation (This Safety
Manual and Technical manual) in regard to all relevant functional safety aspects such as application of use,
installation, operation, maintenance, proof tests, maximum ratings, environmental conditions, repair, etc;
2. Selection of this equipment for use in safety functions and the installation, configuration, overall
validation, maintenance and repair shall only be carried out by competent personnel, observing all
the manufacturer’s conditions and recommendations in the user documentation.
3. All information associated with any field failures of this product should be collected under a
dependability management process (e.g., IEC 60300-3-2) and reported to the manufacturer.
4. The unit should be tested at regular intervals to identify any malfunctions; in accordance with this safety
manual.
XB15 XENON BEACON
Safety Function of XB15 Xenon Beacon:
‘To provide a spherical visual warning light when required’
Architectural constraints:
Type B
HFT=0
SFF =
74.65%
Proof Test Interval
=8760Hrs
[4]
MTTR = 8 Hrs
[4]
SIL 1
Random hardware failures:
λ
DD
= 1.12E-05
λ
DU
= 6.62E-06
λ
SD
= 4.84E-06
λ
SU
= 3.43E-06
Probability of failure on demand:
PFD
AVG
=2.92E-02
(Low Demand Mode)
SIL 1
Probability of Dangerous failure
on safety function:
PFH = 6.62E-06
(High Demand Mode)
SIL 1
Hardware safety integrity
compliance
Route 1
H
Systematic safety integrity
compliance
Route 1
S
Systematic Capability
SC 2 (Ref to 56A24816B)
Overall SIL-capability achieved
SIL 1 (Low Demand)
SIL 1 (High Demand)
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