Eaton XB15 - Functional Safety Assessment - XB15 DC; Functional Safety Assessment - XB15 AC

6
Xenon beacon XB15
English
The telephone initiate versions of the Beacon are not
included in this safety manual.
Under No fault (Normal) Operating conditions the XB15
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 – XB15 DC
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 730hrs.
The results are shown below and are based on Route 1H.
The Beacon is classed as a Type B device.
Safety function:
‘To provide a spherical cycled visual warning light when energized’.
XB15 DC Beacon
Summary of Clauses
2/7.4.2 and 2/7.4.4
XB15 Xenon Beacon
Single Mode (1oo1)
XB15 Xenon Beacon
Redundant Mode (1oo2)
Verdict
Architectural constraints
Safe Failure Fraction (SFF)
HFT=0 HFT=1 Type B
62% 62% SIL 1
Random hardware
failures: [h
-1
]
λ
DD
λ
DU
0.00E+00
5.85E-06
0.00E+00
5.85E-07
Random hardware
failures: [h
-1
]
λ
SD
λ
SU
0.00E+00
9.53E-06
0.00E+00
9.53E-07
Diagnostic coverage (DC) 0.00% 0.00%
PFD @ PTI = 730Hrs, MTTR = 8 Hrs 2.18E-03 2.18E-04 SIL 2 (1oo1)
Average freq. of dangerous failure (high
demand-PFH)[h
-1
]
5.85E-06 5.85E-07 SIL 1 (1oo1)
Hardware safety integrity compliance
[
Route 1
H
Systematic safety integrity compliance See report R56A24816B
Systematic Capability
(SC1, SC2, SC3, SC4)
SC2 (R56A24816B)
Hardware safety integrity achieved Limited to: SIL 1 (1oo1) & SIL 2 (1oo2) due to SFF value.
Assessment of functional safety – XB15 AC
This Beacon 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 XB15 Xenon Beacon against the
requirements of IEC 61508-2 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 B device.
XENON BEACON XB15 TM332 Issue A October 2018 www.eaton.com