<A2. SAFETY INSTRUMENTED SYSTEMS INSTALLATION>
A2-6
IM 01R01B02-00E-E 12th edition October 01, 2014 -00
All Rights Reserved. Copyright © 2003, Rota Yokogawa
Table A2.24: Summary for RAMC ([V2]) with 4-20mA output – Failure rates
Profile 2
Profile 4
Fail Safe Detected (
λ
SD)
0 FIT
0 FIT
Fail Safe Undetected (
λ
SU)
60 FIT
60 FIT
Fail Dangerous Detected (
λ
DD)
260 FIT
344 FIT
Fail Dangerous Undetected (
λ
DU)
193 FIT
200 FIT
SFF
4
62.3%
66.8%
DC
D
57%
63%
MTBF
191 years
166 years
SIL AC
5
SIL1
SIL1
Safety metrics according to ISO 13849-1
6
:
MTTF
d
(years)
252
210
DC
57%
63%
Category (CAT)
CAT 1
CAT 2
Performance Level (required)
PL
r
= c
PL
r
= c
Performance Level (calculated)
4.53E-07 1/h
5.44E-07 1/h
T[Proof] = 1 year
T[Proof] = 5 years
T[Proof] = 10 years
PFDAVG = 9.28E-04
PFDAVG = 4.28E-03
PFDAVG = 8.46E-03
3
The switching contact output is connected to a fail-safe NAMUR amplifier (e.g. Fuchs KF**-SH-Ex1). The failure rates of the
amplifier are not included in the listed failure rates
4
The complete sensor subsystem will need to be evaluated to determine the overall Safe Failure Fraction. The number listed is for
reference only.
5
SIL AC (architectural constraints) means that the calculated values are within the range for hardware architectural constraints for the
corresponding SIL but does not imply all related IEC 61508 requirements are fulfilled.
6
Depending on the application and possible external diagnostics a higher DCD and therefore also a higher category might be possible
to achieve.
7
The switching contact output is connected to a standard switching amplifier (e.g. Fuchs KF**-SR2-Ex*.W). The failure rates of
the amplifier are not included in the listed failure rates.
Summary of Contents for RAMC
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