ABB RET670 - Completing the Test; Multipurpose Protection; General Current and Voltage Protection CVGAPC

Verification of START value and time delay to operate
1.
Check that the settings in the IED are appropriate, especially the START
value and the definite time delay. Set StartFreqGrad, to a rather small
negative value.
2. Supply the IED with three-phase voltages at their rated values.
3. Slowly decrease the frequency of the applied voltage, with an increasing rate-
of-change that finally exceeds the setting of StartFreqGrad, and check that
the START signal appears.
4. Note the operate value and compare it with the set value.
5. Increase the frequency to rated operating conditions, and zero rate-of-change.
6. Check that the START signal resets.
7. Instantaneously decrease the frequency of the applied voltage to a value about
20% lower than the nominal value.
8. Measure the time delay for the TRIP signal, and compare it with the set value.
Extended testing
1. The test above can be repeated to check a positive setting of StartFreqGrad.
2. The tests above can be repeated to check the time to reset.
3. The tests above can be repeated to test the RESTORE signal, when the
frequency recovers from a low value.
13.8.3.2 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.
13.9 Multipurpose protection
13.9.1 General current and voltage protection CVGAPC
Prepare the IED for verification of settings as outlined in section
"Overview" and
section "Preparing for test" in this chapter.
One of the new facilities within the general current and voltage protection function
CVGAPC is that the value, which is processed and used for evaluation in the
function, can be chosen in many different ways by the setting parameters
CurrentInput and VoltageInput.
These setting parameters decide what kind of preprocessing the connected three-
phase CT and VT inputs shall be subjected to. That is, for example, single-phase
quantities, phase-to-phase quantities, positive sequence quantities, negative
sequence quantities, maximum quantity from the three-phase group, minimum
1MRK 504 088-UEN C Section 13
Verifying settings by secondary injection
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Installation and commissioning manual