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1MRK 511 409-UUS Rev. K
12.2.2.3
Secondary injection
The periodic maintenance test is done by secondary injection from a portable test set. Each protection
shall be tested according to the secondary injection test information for the specific protection IED. Only
the setting values adopted shall be checked for each protection function. If the discrepancy between
obtained value and requested set value is too big the setting should be adjusted, the new value recorded
and a note should be made in the test record.
12.2.2.4
Alarm test
When inserting the test handle of RTXP or using FT plugs, the alarm and event signalling is normally
blocked. This is done in the IED by setting the event reporting to Disabled during the test. This can be
done when the test handle is inserted or the IED is set to test mode from the local HMI. At the end of the
secondary injection test it should be checked that the event and alarm signalling is correct by activating
the events and performing some selected tests.
12.2.2.5
Self supervision check
Once secondary testing has been completed, it should be checked that no self-supervision signals are
activated continuously or sporadically. Especially check the time synchronization system, GPS or other,
and communication signals, both station communication and remote communication.
12.2.2.6
Trip circuit check
When the protection IED undergoes an operational check, a tripping pulse is normally obtained on one or
more of the output contacts and preferably on the test switch. The healthy circuit is of utmost importance
for the protection operation. If the circuit is not provided with a continuous trip-circuit supervision, it is
possible to check that circuit is really closed when the test-plug handle has been removed by using a
high-ohmic voltmeter and measuring between the plus and the trip output on the panel. The
measurement is then done through the trip coil of the circuit breaker and therefore the complete trip
circuit is checked.
Trip circuit from trip IEDs to circuit breaker is often supervised by trip-circuit supervision. It can then be
checked that a circuit is healthy by opening tripping output terminals in the cubicle. When the terminal is
opened, an alarm shall be achieved on the signal system after a delay of some seconds.
Phasor measurement unit RES670
Commissioning manual
Note that the breaker must be closed.
Please observe that the test system does not provide built-in security during this test. If
the instrument should be set on Amp instead of Volts, the circuit breaker naturally is
tripped, therefore, great care is necessary.
Remember to close the circuit directly after the test and tighten the terminal carefully.
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Commissioning and maintenance of the fault clearing system
Section 12
SEMOD56528-17 v2
SEMOD56528-20 v5
SEMOD56528-23 v6
SEMOD56528-26 v5
153
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