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Section 10
Testing functionality by secondary injection
10.5.4
10.5.4.1
10.5.4.2
148
Four step residual overcurrent protection, (Zero sequence or
negative sequence directionality) EF4PTOC
Prepare the IED for verification of settings outlined in section
verify
settings".
Four step directional earth fault protection
1.
Connect the test set for single current injection to the appropriate IED terminals.
Connect the injection current to terminals L1 and neutral.
2.
Set the injected polarizing voltage slightly larger than the set minimum
polarizing voltage (default 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.
"Four step directional earth fault
1MRK 506 355-UEN A
"Preparing the IED to
protection", but without
Line distance protection REL670 2.1 IEC
Commissioning manual
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