Measuring The Operating Limit Of Set Values; Completing The Test; Full Scheme Distance Protection, Mho Characteristic Zmhpdis118 - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.4.2.1
11.4.2.2
11.4.3
118

Measuring the operating limit of set values

Procedure:
1. Supply the IED with healthy conditions for at least two seconds.
2. Apply the fault condition and slowly decrease the measured impedance to
find the operate value for of the phase-to-earth loop L3, test point 1,
according to figure 25. Compare the result of the measurement with the
expected value according to table 22.
The corresponding binary signals that inform about the operation of the phase
selection measuring elements are available in the local HMI under
Main menu/Test/Function status/Impedance Protection/
PhaseSelection(PDIS, 21)/FDPSPDIS:x.
3. Repeat steps 1 to 2
according to figure
When the load encroachment characteristic is deliberately set
very high in order not to have an influence, then the test points
2 and 5 can be replaced by test point 7.
4. Repeat steps 1 to 3
— L2 according to figure

Completing the test

Continue to test another function or end the test by changing the TESTMODE
setting to Off. Restore connections and settings to their original values, if they were
changed for testing purposes.
Full scheme distance protection, mho characteristic
ZMHPDIS
Prepare the IED for verification of settings outlined in Section
to verify settings".
Consider releasing of the zone to be tested by setting the phase selector FMPSPDIS
to On.
Keep the current constant when measuring operating characteristics. Keep the
current as close as possible to its rated value or lower. But make sure it is higher
than the set minimum operating current.
Ensure that the maximum continuous current in an IED does not exceed four times
its rated value, if the measurement of the operating characteristics runs under
constant voltage conditions.
To verify the mho characteristic, at least two points should be tested.
to find the operate values for the remaining test points
25 and table 22.
to find the operate value for the phase-to-phase fault in L1
26 and table 23.
1MRK 504 165-UEN A
"Preparing the IED
Transformer protection RET670 2.2 IEC
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