Operation Guide P341/EN O/B11
Commissioning and CHAPTER 3
Maintenance Page 19/80
MiCOM P341
• Step through the settings using the relay’s operator interface and compare them
with the original application-specific setting record.
Unless previously agreed to the contrary, the application-specific programmable
scheme logic will not be checked as part of the commissioning tests.
Due to the versatility and possible complexity of the programmable scheme logic, it is
beyond the scope of these commissioning instructions to detail suitable test
procedures. Therefore, when programmable scheme logic tests must be performed,
written tests which will satisfactorily demonstrate the correct operation of the
application-specific scheme logic should be devised by the Engineer who created it.
These should be provided to the Commissioning Engineer together with the diskette
containing the programmable scheme logic setting file.
5.3 Demonstrate correct relay operation
This test, performed on stage 1 of the overcurrent protection function in setting group
1, demonstrates that the relay is operating correctly at the application-specific
settings.
It is not considered necessary to check the boundaries of operation where cell [3502:
GROUP 1 OVERCURRENT,
f>1 Directional] is set to ‘Directional Fwd’ or ‘Directional
Rev’ as tests detailed already confirm the correct functionality between current and
voltage inputs, processor and outputs, and earlier checks confirmed the measurement
accuracy is within the stated tolerance.
5.3.1 Connect the test circuit
Determine which output relay has been selected to operate when an
f>1 trip occurs
by viewing the relay’s programmable scheme logic.
The programmable scheme logic can only be changed using the appropriate
software. If this software has not been available then the default output relay
allocations will still be applicable.
If the trip outputs are phase-segregated (i.e. a different output relay allocated for
each phase), the relay assigned for tripping on ‘A’ phase faults should be used.
If stage 1 is not mapped directly to an output relay in the programmable scheme
logic, output relay 3 should be used for the test as it operates for any trip condition.
The associated terminal numbers can be found either from the external connection
diagram (Appendix 2) or Table 5.
Connect the output relay so that its operation will trip the test set and stop the timer.
Connect the current output of the test set to the ‘A’ phase current transformer input of
the relay (terminals C3 and C2 where 1A current transformers are being used and
terminals C1 and C2 for 5A current transformers).
If [3502: GROUP 1 OVERCURRENT,
f>1 Direction] is set to ‘Directional Fwd’, the
current should flow out of terminal C2 but into C2 if set to ‘Directional Rev’. Also
apply rated voltage to terminals C20 and C21.
Ensure that the timer will start when the current is applied to the relay.
Note: If the timer does not start when the current is applied and stage 1 has been
set for directional operation, the connections may be incorrect for the
direction of operation set. Try again with the current connections reversed.
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