Four Step Non-Directional Earth Fault Protection; Completing The Test; Four Step Negative Sequence Overcurrent Protection Ns4Ptoc - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.5.4.2
11.5.4.3
11.5.5
176
Connect the injection current to terminals L1 and neutral.
2. Set the injected polarizing voltage slightly larger than the set minimum
polarizing voltage (5% of Ur) and set the injection current to lag the voltage
by an angle equal to the set reference characteristic angle (AngleRCA), if the
forward directional function is selected.
If reverse directional function is selected, set the injection current to lag the
polarizing voltage by an angle equal to RCA+ 180°.
3. Increase the injected current and note the value at which the studied step of
the function operates.
4. Decrease the current slowly and note the reset value.
5. If the test has been performed by injection of current in phase L1, repeat the
test, injecting current into terminals L2 and L3 with a polarizing voltage
connected to terminals L2, respectively L3.
6. Block lower set steps when testing higher set steps according to the
instructions that follow.
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.

Four step non-directional earth fault protection

1. Do as described in
applying any polarizing voltage.

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.
Four step negative sequence overcurrent protection
NS4PTOC
Prepare the IED for verification of settings as outlined in section
test" in this chapter.
"Four step directional earth fault
1MRK 504 165-UEN A
SEMOD53296-202 v4
protection", but without
SEMOD53296-122 v4
GUID-EB1A8DFD-5BAC-4024-ADA2-D9BE7A2B50A0 v2
"Preparing for
Transformer protection RET670 2.2 IEC
Commissioning manual