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1MRK 504 165-UEN Rev. K
1.
Connect the test set for single-phase current injection to the protection terminals connected to
the CT in the power transformer neutral-to-earth circuit.
2.
Increase the injection current and note the operating value of the protection function.
3.
Check that all trip and start signals appear according to the configuration logic.
4.
Decrease the current slowly from operate value and note the reset value.
5.
Connect the timer and set the current to ten times the value of the IdMin setting.
6.
Switch on the current and note the operate time.
7.
Connect the test set to terminal L1 and neutral of the three-phase current input configured to
REFPDIF. Also inject a current higher than half the IdMin setting in the neutral-to-earth circuit
with the same phase angle and with polarity corresponding to an internal fault.
8.
Inject current into terminals L2 and L3 in the same way as in step 7 above and note the operate
and reset values.
9.
Inject a current equal to 10% of rated current into terminal L1.
10.
Inject a current in the neutral-to-earth circuit with the same phase angle and with polarity
corresponding to an external fault.
11.
Finally check that trip information is stored in the event and disturbance recorder.
11.3.3.3
Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to Off. Restore
connections and settings to the original values, if changed for testing purposes.
11.3.4
Additional security logic for differential protection LDRGFC
11.3.4.1
Verifying the settings
Prepare the IED for verification of settings outlined in section 1 "Overview" and section 2 "Preparing
for test" in this chapter.
Current variation local criteria
Procedure
1.
Set Operation to On.
2.
Connect the test set for three phase current injection to the appropriate IED terminals.
3.
Inject symmetrical phase currents equal to half the rated current
4.
Increase the injected current in phase L1 slowly in steps less than the set ICV>, to a value
higher than set ICV>. No signal shall be activated.
5.
Decrease the injected current in phase L1 to half the rated current.
6.
Increase the injected current in phase L1 in a step by more than the set ICV>. Start shall be
activated.
Undervoltage criteria
Procedure
1.
Connect the test set for three phase current injection and three phase voltage to the
appropriate IED terminals.
2.
Inject symmetrical phase voltages equal to the rated voltage.
3.
Decrease the injected voltage in phase L1 and note the operated value (start value) of the
function.
4.
Increase the voltage slowly and note the reset value.
5.
Connect a trip output contact to a timer.
6.
Reduce the injected voltage stepwise to 90 % of the operate level, and check the time delay.
7.
Repeat points 3– 6 for phases L2 and L3.
Transformer protection RET670
Commissioning manual
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Section 11
Testing functionality by secondary injection
SEMOD55252-118 v5
GUID-0E064528-0E70-4FA1-87C7-581DADC1EB55 v2
GUID-D9F626D4-4038-416F-888E-D3DB5047E79A v1
GUID-804E13B6-DC31-487B-A582-7886B1EF3EB7 v3
GUID-57075848-249D-4F53-AB4D-A0DF2A04AC7C v2
95
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