7.
Connect a trip output contact to a timer.
8.
Set the injected current to 200% of the operate level of the tested step, switch on
the current and check the time delay.
For inverse time curves, check the operate time at a current equal to 110% of the
operate current for
txMin
.
9.
Check that all operate and start contacts operate according to the configuration
(signal matrixes)
10. Reverse the direction of the injected current and check that the step does not
operate.
11. Check that the protection does not operate when the polarizing voltage is zero.
12. Repeat the above described tests for the higher set steps.
13. Finally, check that start and trip information is stored in the event menu.
10.4.4.2
Four step non-directional earth fault protection
1.
Do as described in
"Four step directional earth fault protection"
, but without
applying any polarizing voltage.
10.4.4.3
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.
10.4.5
Four step negative sequence overcurrent protection
NS4PTOC
Prepare the IED for verification of settings as outlined in section
and
section
in this chapter.
When inverse time overcurrent characteristic is selected, the operate
time of the stage will be the sum of the inverse time delay and the set
definite time delay. Thus, if only the inverse time delay is required, it
is important to set the definite time delay for that stage to zero.
Procedure
1.
Connect the test set for injection of three-phase currents and voltages to the
appropriate CT and VT inputs of the IED.
2.
Inject pure negative sequence current, that is, phase currents with exactly same
magnitude, reversed sequence and exactly 120° phase displaced into the IED
with an initial value below negative sequence current pickup level. No output
Section 10
1MRK 511 360-UEN A
Testing functionality by secondary injection
90
Bay control REC670 2.1 IEC
Commissioning manual
