Yokogawa EJX440A - Manual (Page 68)

<Appendix 1. Safety Instrumented Systems Installation>
A-2
IM 01C25T01-01E
Table A1.2.5 Proof Testing
Testing method Tools required Expected outcome Remarks
Functional test:
1. Follow all Management of Change
procedures to bypass logic solvers if
necessary.
2. Execute HART/BRAIN command to
send value to high alarm (21.5 mA) and
verify that current has reached this level.
3. Execute HART/BRAIN command to
send value to low alarm (3.6 mA) and
verify that current has reached this level.
4. Restore logic solvers operation and
verify.
• Handheld terminal Proof Test Coverage
=52%
The output needs to be
monitored to assure that the
transmitter communicates
the correct signal.
Perform three point calibration along with
the functional test listed above.
• Handheld terminal
• Calibrated pressure
source
Proof Test Coverage
=99%
A1.2.6 Repair and Replacement
If repair is to be performed with the process online
the EJX will need to be bypassed during the
repair. The user shall setup appropriate bypass
procedures.
In the unlikely event that the EJX has a failure,
the failures that are detected shall be reported to
Yokogawa.
When replacing the EJX, the procedure in the
installation manual shall be followed.
The personnel performing the repair or replacement
of the EJX shall have a sufficient skill level.
A1.2.7 Startup Time
The EJX generates a valid signal within 1 second of
power-on startup.
A1.2.8 Firmware Update
In case firmware updates are required, they
will be performed at factory. The replacement
responsibilities are then in place. The user will not
be required to perform any firmware updates.
A1.2.9 Reliability Data
A detailed Failure Mode, Effects, and Diagnostics
Analysis (FMEDA) report is available from
Yokogawa with all failure rates and failure modes.
The EJX is certified up to SIL2 for use in a simplex
(1oo1) configuration, depending on the PFDavg
calculation of the entire Safety Instrumented
Function.
The development process of the EJX is certified up
to SIL3, allowing redundant use of the transmitter
up to this Safety Integrity Level, depending
the PFDavg calculation of the entire Safety
Instrumented Function.
When using the transmitter in a redundant
configuration, the use of a common cause factor
(β-factor) of 2% is suggested. (However, if the
redundant transmitters share an impulse line or if
clogging of the separate impulse lines is likely, a
common cause factor of 10% is suggested.)
Note that the failure rates of the impulse lines need
to be accounted for in the PFDavg calculation.
A1.2.10 Lifetime Limits
The expected lifetime of the EJX is 50 years. The
reliability data listed the FMEDA report is only valid
for this period. The failure rates of the EJX may
increase sometime after this period. Reliability
calculations based on the data listed in the FMEDA
report for EJX lifetimes beyond 50 years may yield
results that are too optimistic, i.e. the calculated
Safety Integrity Level will not be achieved.
A1.2.11 Environmental Limits
The environmental limits of the EJX are specified in
the user’s manual IM 01C25.
A1.2.12 Application Limits
The application limits of the EJX are specified in the
user’s manual IM 01C25. If the transmitter is used
outside of the application limits, the reliability data
listed in A1.2.9 becomes invalid.