7
LED Beacon LD15
English
Assessment of functional safety – LD15 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 LD15 LED 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.
Safety function:
‘To provide an intermittent or permanent spherical visual warning light upon demand’.
LD15 DC Beacon
Summary of
Clauses
2/7.4.2 and 2/7.4.4
LD15 LED Beacon
Single Mode
(1oo1)
LD15 LED Beacon
Redundant Mode
(1oo2)
Verdict
Architectural
constraints Safe
Failure Fraction (SFF)
HFT=0
HFT=1
Type B
67%
67%
SIL 1
(1oo1)
SIL 2
(1oo2)
Random
hardware
failures: [h
-1
]
λ
DD
λ
DU
6.45E-09
6.247E-08
6.45E-10
6.247E-09
Random
hardware
failures: [h
-1
]
λ
SD
λ
SU
0.00E+00
1.21E-07
0.00E+00
1.21E-08
Diagnostic coverage
(DC)
0.00%
0.00%
PFD @ PTI = 8760Hrs,
MTTR = 8 Hrs
2.74E-04
2.742E-05
SIL 3
(1oo1)
Average freq. of
dangerous failure
(high demand-PFH)[h
-1
]
6.247E-08
6.247E-09
SIL 4
(1oo1)
Hardware safety
integrity compliance
Route 1
H
Systematic safety
integrity compliance
Route 1
S
Systematic Capability
(SC1, SC2, SC3, SC4)
SC2
Hardware safety
integrity achieved
Limited to: SIL 1 (1oo1) & SIL 2 (1oo2) due to
SFF value.
LED BEacon LD15
TM334 Issue A
October
2018 www.eaton.com
