87
Distance protection Chapter 11
Verifying settings by secondary
injection
2. Apply the fault condition to find the operating time for the
phase-to-phase loop according to test point P10 in figure 26
and
table 15
for zone 1. Compare the result of the measurement with the
setting t1PP.
3. Repeat steps 1 to 2 to find the operating time for the phase-to-earth
loop according to test point P10 in figure 27
and table 15. Compare
the result of the measurement with the setting t1PE.
4. Repeat steps 1 to 2 to find the operating time for all other used mea-
suring zones.
Observe that the zone that are not tested has to be blocked and the zone
that is tested has to be released.
When the load shaped characteristic is activated (OperationLdCmp=On)
the test point for phase to phase faults is P12 in figure 26
and table 15and
for phase — earth faults according to P12 in figure 27
and table 16.
5.1.3 Completing the test
Continue to test another function or end the test by changing the test mode setting to off.
5.2 Phase selection with load enchroachment (PDIS, 21)
Prepare the terminal for verification of settings as outlined in section 2 "Preparing for test" in
this chapter.
The phase selectors operate on the same measuring principles as the impedance measuring
zones. So it is necessary to follow the same principles as for distance protection, when perform-
ing the secondary injection tests.
Measure operating characteristics during constant current conditions. Keep the measured current
as close as possible to its rated value or lower. But ensure that it is higher than 30% of the rated
current.
Ensure that the maximum continuous current of a terminal does not exceed four times its rated
value, if the measurement of the operating characteristics runs under constant voltage condi-
tions.
To verify the settings the operating points according to figures 28, 29, and 30 should be tested.
See also table 30
for information.