63
Current reversal and weak end infeed
logic for residual
overcurrent protection (EFCA)
Chapter 10
Verifying settings by secondary
injection
4
Current reversal and weak end infeed logic for
residual overcurrent protection (EFCA)
Prepare the terminal for verification of settings as outlined in section “Preparing for
test” in this chapter.
First, test the time delayed residual overcurrent protection according to the correspond-
ing instruction. Then continue with the instructions below.
Logical signals for current reversal and WEI logic for residual overcurrent protection
are available under menu tree:
Service Report/Functions/EarthFault/ComlRevWeiEF/FuncOutputs
4.1
Testing the current reversal logic
Procedure
1.
Inject the polarising voltage 3U0 to 5% of Ub and the phase
angle between voltage and current to 155°, the current lead-
ing the voltage.
2.
Inject current (155° leading the voltage) in one phase to about
110% of the setting operating current (IN>Dir).
3.
Check that the EFCA-IRVL output is activated after the set
time (tPickUp).
4.
Abruptly reverse the current to 65° lagging the voltage, to op-
erate the forward directional element.
5.
Check that the EFCA-IRVL output still is activated after the re-
versal with a time delay that complies with the setting (tDe-
lay).
6.
Switch off the polarising voltage and the current.
4.2
Testing the weak-end-infeed logic
4.2.1
If setting parameter WEI=Echo
Procedure
1.
Inject the polarising voltage 3U0 to 5% of Ub and the phase
angle between voltage and current to 155°, the current lead-
ing the voltage.
2.
Inject current (155° leading the voltage) in one phase to about
110% of the setting operating current (IN>Dir).
