Endress+Hauser Liquiphant M/S with electronic Insert FEL56 Operator's manual

Point level measuring system
Products Solutions Services
Special Documentation
Liquiphant M/S with electronic
insert FEL56 + Nivotester
FTL325N
Functional Safety Manual
SD01521F/00/EN/04.19
71433131
2019-03-05
CH1
CH1
[Ex ia]
CH1 CH2
CH2
CH3
CH3
[Ex ia]

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Table of contents
Declaration of conformity ..................... 3
General .................................... 4
Other safety-related characteristic values ............. 5
Useful lifetime of electrical components .............. 13
Certificate ................................ 14
Document information ...................... 15
Document function ........................... 15
Symbols used ............................... 15
Supplementary device documentation ............... 16
Permitted devices types ..................... 18
SIL label on the nameplate ...................... 19
Safety function ............................ 20
Definition of the safety function ................... 20
Restrictions for use in safety-related applications ....... 20
Use in safety instrumented systems ............ 23
Device behavior during operation .................. 23
Device configuration for safety-related applications ...... 23
Proof-testing ............................... 27
Life cycle ................................. 38
Requirements for personnel ..................... 38
Installation ................................. 38
Operation ................................. 38
Maintenance ............................... 38
Repair .................................... 38
Modification ................................ 39
Decommissioning ............................ 39
Appendix ................................ 40
Structure of the measuring system ................. 40
Commissioning or proof test report ................. 42
Further information ........................... 44
Version history .............................. 44

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Declaration of conformity
A0025774

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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A0025775
General The components can be operated as different versions:
• Version I (→  6)
One Liquiphant for the direct activation of a NAMUR switching unit (e.g. transmitter, safety-
related PLC) via the NAMUR interface according to EN 50227 (DIN 19234; NAMUR) or
IEC 60947-5-6.
• Version II (→  7)
One Liquiphant with a 1-channel Nivotester, for the activation of an actuator or a safety-related
PLC via switching contacts, for instance
• Version III (→  8)
One Liquiphant with a 3-channel Nivotester, switching contacts are switched in series

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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• Version IV (→  9)
Two Liquiphant devices with a 3-channel Nivotester, switching contacts are switched in series
• Version V (→  11)
Three Liquiphant devices with a 3-channel Nivotester, all channels are used, evaluation is
performed in a safety-related PLC, for example
• Version VI (→  13)
Three Liquiphant devices with a 3-channel Nivotester, only channel 1 has a SIL-specific
monitoring function. Channels 2 and 3 are used for level control of the same level (e.g. Δs). This
level control may not be considered as a safety measure as part of functional safety according to
EN 61508.
NOTICE
Measuring another, independent level (e.g. in a second tank)
‣The remaining channels may not be used for other levels.
Other safety-related
characteristic values
Please note the following for the tables below:
• A common cause factor β = 10 % has been assumed in the calculations indicated below.
• For multi-channel systems, the PFDavg values already contain common cause failures for the
specific wiring scheme.
• The PFDavg values only apply to the particular wiring scheme for which the values have been
calculated. They are not a suitable basis for making calculations for other wiring schemes.
The use of NC contacts instead of NO contacts, in particular, is not permitted for operation
according to SIL specifications.
• The wiring scheme indicates the number of devices and the circuitry of the level relay
contacts (open when required (demand mode)).
• If there are several devices in a wiring scheme, all the devices have the same settings shown.
• The tables show safety-related values and wiring options for the measuring system.
• FIT = Failure in Time, 1 FIT = 10-9 l/h.

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Specific functional safety parameters:
Version I: Liquiphant M/S
Characteristics as per IEC
61508
Value
Safety function MIN MAX
Example
Wiring scheme
A
A Other safety equipment e.g. actuator/safety-related PLC
SIL 2
HFT 0
Device type B
Mode of operation Low demand mode
SFF 68 % 74 %
MTTR 8 h
λsd 1) 56 FIT 68 FIT
λsu 1) 80 FIT 82 FIT
λdd 1) 7 FIT
λdu 1) 67 FIT 54 FIT
PFDavg for T1 = 1 year 2.92 x 10-4 2.36 x 10-4
MTBF 543 years
Diagnostic test interval 2) ≤60 s
Fault reaction time 3) ≤3 s
System reaction time 4) 1 s (covered > free) 0.5 s (free > covered)
PTC test sequence A 5) 93 %
PTC test sequence C 6) - 93 %
1) This value takes into account failure types relevant to the function of the electronic components according
to Siemens SN29500.
2) During this time, all diagnostic functions are executed at least once.
3) Time between error detection and error response.
4) Step response time as per DIN EN 61298-2.
5) Proof test coverage when the level is approached, or when the sensor is removed and the tines are
immersed in a medium of similar density and viscosity.
6) Proof test coverage when checking the switch point under reference operating conditions.

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Version II: Liquiphant M/S; 1-channel Nivotester FTL325N
Characteristics as per IEC
61508
Value
Safety function MIN MAX
Example
Wiring scheme
ACH1
A Other safety equipment e.g. actuator/safety-related PLC
SIL 2
HFT 0
Device type B
Mode of operation Low demand mode
SFF 85 % 86 %
MTTR 8 h
λsd 1) 56 FIT 68 FIT
λsu 1) 542 FIT
λdd 1) 9 FIT
λdu 1) 110 FIT 97 FIT
PFDavg for T1 = 1 year 4.83 x 10-4 4.27 x 10-4
MTBF 159 years
Diagnostic test interval 2) ≤60 s
Fault reaction time 3) ≤3 s
System reaction time 4) 1 s (covered > free) 0.5 s (free > covered)
PTC test sequence A 5) 88 %
PTC test sequence B 6) 34 % 38 %
PTC test sequence C 7) - 88 %
1) This value takes into account failure types relevant to the function of the electronic components according
to Siemens SN29500.
2) During this time, all diagnostic functions are executed at least once.
3) Time between error detection and error response.
4) Step response time as per DIN EN 61298-2.
5) Proof test coverage when the level is approached, or when the sensor is removed and the tines are
immersed in a medium of similar density and viscosity.
6) Proof test coverage when simulation is performed on the Nivotester by activating the test button.
7) Proof test coverage when checking the switch point under reference operating conditions.

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Version III: Liquiphant M/S; 3-channel Nivotester FTL325N, CH2 and CH3 in series
Characteristics as per IEC
61508
Value
Safety function MIN MAX
Example
Wiring scheme
A
B C
A
(1oo2)
CH2 CH2
CH3 CH3
CH1 CH1
A Other safety equipment e.g. actuator/safety-related PLC
B Possibility 1
C Possibility 2; 1oo2 assessment
SIL 2
HFT 0
Device type B
Mode of operation Low demand mode
SFF 92 % 93 %
MTTR 8 h
λsd 1) 63 FIT 76 FIT
λsu 1) 803 FIT
λdd 1) 7 FIT
λdu 1) 78 FIT 65 FIT
PFDavg for T1 = 1 year 3.41 x 10-4 2.85 x 10-4
MTBF 120 years
Diagnostic test interval 2) ≤60 s
Fault reaction time 3) ≤3 s
System reaction time 4) 1 s (covered > free) 0.5 s (free > covered)
PTC test sequence A 5) 93 %
PTC test sequence B 6) 52 % 57 %
PTC test sequence C 7) - 93 %
1) This value takes into account failure types relevant to the function of the electronic components according
to Siemens SN29500.
2) During this time, all diagnostic functions are executed at least once.
3) Time between error detection and error response.
4) Step response time as per DIN EN 61298-2.
5) Proof test coverage when the level is approached, or when the sensor is removed and the tines are
immersed in a medium of similar density and viscosity.
6) Proof test coverage when simulation is performed on the Nivotester by activating the test button.
7) Proof test coverage when checking the switch point under reference operating conditions.

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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Version IV: 2 Liquiphant M/S; 3-channel Nivotester FTL325N
Characteristics as per IEC
61508
Value
Safety function MIN MAX
Example
Wiring scheme
A
B C
A
(1oo3)
CH2 CH2
CH3 CH3
CH1 CH1
A Other safety equipment e.g. actuator/safety-related PLC
B Possibility 1
C Possibility 2; 1oo3 assessment
SIL 2
HFT 1
Device type B
Mode of operation Low demand mode
SFF 99 %
MTTR 8 h
λsd 1) 135 FIT 159 FIT
λsu 1 225 FIT 1 203 FIT
λdd 1 FIT
λdu 16 FIT 15 FIT
PFDavg for T1 = 1 year 7.07 x -10-5 6.52 x 10-5
MTBF 83 years
Diagnostic test interval 2) ≤60 s
Fault reaction time 3) ≤3 s
System reaction time 4) 1 s (covered > free) 0.5 s (free > covered)
PTC test sequence A 5) 88 %
PTC test sequence B 6) 34 % 38 %
PTC test sequence C 7) - 88 %
1) This value takes into account failure types relevant to the function of the electronic components according
to Siemens SN29500.
2) During this time, all diagnostic functions are executed at least once.
3) Time between error detection and error response.
4) Step response time as per DIN EN 61298-2.
5) Proof test coverage when the level is approached, or when the sensor is removed and the tines are
immersed in a medium of similar density and viscosity.
6) Proof test coverage when simulation is performed on the Nivotester by activating the test button.
7) Proof test coverage when checking the switch point under reference operating conditions.

Liquiphant M/S with electronic insert FEL56 + Nivotester FTL325N
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The failure rates are based on an analysis in accordance with DIN EN 61508-6: 2011-02, Table
D.4, "Using the β-factor to calculate the probability of failure in an E/E/PE safety-related system
due to common cause failures". The calculation gives a β-factor of 10 %. This factor is based on
the failure rates indicated above. If additional measures are implemented during installation to
prevent common cause errors as defined in Table D.1, the β-factor can possibly be reduced to
5 %. Possible measures are:
• Sensors installed in a physically separate location
• Cable routed separately between the Liquiphant and Nivotester
• Separate protection from environmental influences: impact, sunshine, EMC protection and/or
overvoltage
• Use of different sensor materials, and combination of high-temperature and normal version