Four Step Non-Directional Ground Fault Protection - ABB RET670 Commissioning Manual

1MRK 504 154-UUS B
11. Check that the protection does not trip when the polarizing voltage is zero.
12. Repeat the above described tests for the higher set steps.
13. Finally, check that pickup and trip information is stored in the event menu.
10.5.4.2

Four step non-directional ground fault protection

1. Do as described in
polarizing voltage.
10.5.4.3 Completing the test
Continue to test another function or end the test by changing the
Restore connections and settings to their original values, if they were changed for testing
purposes.
10.5.5 Four step negative sequence overcurrent protection NS4PTOC
(46I2)
Prepare the IED for verification of settings as outlined in section
section "Preparing for test"
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 signals should be activated. Check under
NS4PTOC function Service Values that correct I2 magnitude is measured by the function.
3. Set the injected negative sequence polarizing voltage slightly larger than the set minimum
polarizing voltage (default 5 % of Vn) and set the injection current to lag the voltage by an
angle equal to the set reference characteristic angle (
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.
4. Increase the injected current and note the value at which the studied step of the function
trip.
5. Decrease the current slowly and note the reset value.
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 trip level of the tested step, switch on the current and
check the time delay.
Commissioning manual
"Four step directional ground fault
in this chapter.
When inverse time overcurrent characteristic is selected, the trip 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.
Testing functionality by secondary injection
protection", but without applying any
TestMode setting to Disabled .
GUID-EB1A8DFD-5BAC-4024-ADA2-D9BE7A2B50A0 v1
"Requirements" and
GUID-F7AA2194-4D1C-4475-8853-C7D064912614 v4
GUID-F973601F-BC67-4E4F-A4CA-BE6253E2FB92 v3
180° - AngleRCA ) if the forward
Section 10
SEMOD53296-202 v4
SEMOD53296-122 v4
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