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6.5.1.2
Earth fault element EF1 to EF4 and SEF1 to SEF4
The earth fault element is checked on the operating current value and operating time for IDMT
curve.
Operating current check
The testing circuit is shown in Figure 6.5.3.
+
Single-phase
current
−
source
+
DC
power
−
supply
+
DC
voltmeter
0V
The output signal of testing element is assigned to the monitoring jack A.
The output signal numbers of the elements are as follows:
Element
EF1D
EF2D
EF3D
EF4D
• Enter the signal number to observe the operation at the monitoring jack A as shown in
Section 6.5.1.
• Apply a test current and change the magnitude of the current applied and measure the value
at which the element operates.
Check that the measured value is within 5% of the setting value.
A
Figure 6.5.3 Operating Current Value Test
Signal No.
Element
100
SEF1D
101
SEF2D
102
SEF3D
103
SEF4D
⎯
⎯
256
6 F 2 S 0 8 4 2
GRD150
I a
TB1
-1
-2
I e
-7
-8
I se
-9
-10
Monitoring
jack
TB2 -A9
-B9
E
Signal No.
104
105
106
107
A
0V
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