3
Xenon beacon - SM87HXB & SM87XBT
English
The safety function of the Beacon is to provide an inter-
mittent spherical visual warning light when the correct
voltage is applied to the unit. The DC versions of the
Beacon are designed to operate on a supply voltage
tolerance of +/- 20%; the AC versions of the beacon are
designed to operate on a supply voltage tolerance of
+/- 10%.
The telephone initiate versions of the Beacon are not
included in this safety manual.
Under No fault (Normal) Operating conditions the
SM87HXB Beacon will provide a spherical visual warning
light when required by the system.
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
The SM87HXB Call Point is intended for use in a safety
system conforming to the requirements of IEC61508.
UL has conducted a Failure Modes Effect and Diagnostic
Analysis (FMEDA) of the SM87HXB Beacon against the
requirements of IEC61508-2 using a proof test interval of
8760hrs.
The results are shown below and are based on Route 1
H
The Beacon is classed as a Type A device.
SM87HXb beacon
Safety Function of SM87HXB Beacon:
‘To provide a spherical cycled visual warning light when energised’
Architectural
constraints:
Type A
HFT=0
SFF= 73%
Proof Test Interval
=8760Hrs
MTTR = 8 Hrs
SIL2
Random hardware
failures:
λ
DD
= 0
λ
DU
= 2.96E-07
λ
SD
= 0
λ
SU
= 8.12E-07
Probability of failure
on demand:
PFD
AVG
=1.30E-03
(Low Demand Mode)
SIL2
Probability of
Dangerous failure on
safety function:
PFH = 2.96E-07
(High Demand
Mode)
SIL2
Hardware safety
integrity compliance
Route 1
H
Systematic safety
integrity compliance
Route 1
S
Systematic Capability
SC2
Overall SIL-capability
achieved
SIL 2 (Low Demand)
SIL 2 (High Demand)
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.
Xenon beacon - SM87HXb & SM87XbT- drafT 1
TM001 Issue J February 2023 www.eaton.com
