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Section 11
Testing functionality by secondary injection
8.
Inject symmetrical phase voltages equal to the rated voltage.
9.
Decrease the injected phase-phase voltage L1-L2 and note the operated value (start value) of
the function.
10.
Increase the voltage slowly and note the reset value.
11.
Connect a trip output contact to a timer.
12.
Reduce the injected voltage stepwise to 90 % of the operate level, and check the time delay.
13.
Repeat points 9 – 12 for phases L2-L3 and L3-L1.
Zero sequence overcurrent criteria
Procedure
1.
Connect the test set for three phase voltage injection (L1, L2, L3) or residual voltage injection
(N) to the appropriate IED terminals. This is dependent on how the IED is fed from the CT .
2.
Increase the injected zero sequence current and note the operate value (start value) of the
studied step of the function.
3.
Decrease the current slowly and note the reset value.
4.
Connect a trip output contact to a timer.
5.
Set the injected current to 200 % of the operate level of the tested stage, switch on the current
and check the time delay.
Low current criteria
Procedure
1.
Connect the test set for three phase current injection to the appropriate IED terminals.
2.
Inject a symmetrical three phase current larger than the set value IUC<
3.
Decrease the injected current in phase L1 and note the operate value (start value) of the
studied step of the function.
4.
Increase the current slowly and note the reset value.
5.
Connect a trip output contact to a timer.
6.
Decrease the injected current stepwise to 50 % of the operate level and check the time delay.
7.
Repeat steps 3 – 6 for phases L2 and L3.
11.3.4.2
Completing the test
Continue to test another function or end the test by changing the test mode setting to off. Restore
connections and settings to their original values, if they were changed for testing purposes.
11.3.5
Self-adaptive differential protection for two-winding power
transformers PSTPDIF
11.3.5.1
Preparing the function for testing
Prepare the IED in general for verification of settings outlined in Section
settings.
Navigate to Main menu/Test/Function test mode and make sure that only the PSTPDIF function
and associated trip function blocks are enabled. All other protection functions, which may interfere
with testing or tripping shall have the setting Blocked set to Yes.
96
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1MRK 504 165-UEN Rev. K
GUID-27C0852A-008D-4107-8346-AB6A85043B7E v2
GUID-64C0F94F-5DC8-476C-B8B5-2B80F2B42692 v2
GUID-BE74F565-7465-4300-B2A6-D99CE8844147 v2
GUID-8C8A342F-0819-4C6E-A32F-E01DB398B8ED v1
GUID-E2D0D0CB-FA4D-4ED0-9BBB-2D1440804F83 v2
Preparing the IED to verify
Transformer protection RET670
Commissioning manual
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