Current Reversal And Weak End Infeed Logic For Residual Overcurrent Protection (Psch, 85) - ABB REL670 Installation And Commissioning Manual

12.4.2
12.5
12.5.1
154
Scheme communication
6. Switch the fault current on (110% of the setting) and measure the op-
erating time of the EFC logic.
Use the TRIP signal from the configured binary output to stop the timer.
7. Compare the measured time with the setting for tCoord .
8. Activate the BLOCK digital input.
9. Switch the fault current on (110% of the setting) and wait for a period
longer than the set value tCoord.
No TRIP signal should appear.
10. Switch the fault current and the polarizing voltage off.
11. Reset the CR binary input and the BLOCK digital input.
Completing the test
Continue to test another function or end the test by changing the test mode setting to off.
Current reversal and weak end infeed logic for residual
overcurrent protection (PSCH, 85)
Prepare the IED for verification of settings as outlined in
"Preparing for test" in this chapter.
First, test the time delayed residual overcurrent protection according to the corresponding in-
struction. Then continue with the instructions below.
Logical signals for current reversal and WEI logic for residual overcurrent protection are avail-
able under menu tree:
Test\Functio status\Current protec-
tion\ResidualOverCurrent4Step(PEFM,51N/67N)\TEFnn
Testing the current reversal logic
Procedure
1. Inject the polarizing voltage 3U0 to 5% of UBase (directional TEF)
and the phase angle between voltage and current to 155 ° , the current
leading the voltage.
Inject current (155 ° leading the voltage) in one phase to about 110%
2.
of the setting operating current ( IN>Dir ).
3. Check that the IRVL output is activated after the set time ( tPickUp ).
Abruptly reverse the current to 65 ° lagging the voltage, to operate
4.
the forward directional element.
5. Check that the IRVL output still is activated after the reversal with a
time delay that complies with the setting ( tDelay ).
6. Switch off the polarizing voltage and the current.
Chapter 11
Verifying settings by secondary
section 1 "Overview" and
injection
section 2