ABB RELION RET670, Commissioning Manual

Page: 232 / 328

6. Check that the PICKUP 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 PickupFreqGrad .
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.
11.7.3.2 Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to
Disabled . Restore connections and settings to their original values, if they were changed
for testing purposes.
11.8 Multipurpose protection
11.8.1 General current and voltage protection CVGAPC
Prepare the IED for verification of settings as outlined in section "Requirements" 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 quantity from the three-phase group,
difference between maximum and minimum quantities (unbalance) can be derived and
then used in the function.
Due to the versatile possibilities of CVGAPC itself, but also the possibilities of logic
combinations in the application configuration of outputs from more than one CVGAPC
function block, it is hardly possible to define a fully covering general commissioning test.
Section 11
1MRK 504 165-UUS -
Testing functionality by secondary injection
226 Transformer protection RET670 2.2 ANSI
Commissioning manual