Earth Fault Protection; Transient Overreach And Overshoot - GE MiCOM P747 Agile Technical Manual

MiCOM P747
3.5

EARTH FAULT PROTECTION

Pick-up (IDMT and DT)
Drop-off (IDMT and DT)
Min. trip level (IDMT elements)
IDMT characteristic shape
IEEE reset
DT operation
DT reset
IDMT pick-up
DT pick-up
Drop-off (IDMT and DT)
IDMT operate
DT operate
DT reset
Overshoot of overcurrent elements
3.6

TRANSIENT OVERREACH AND OVERSHOOT

Additional tolerance due to increasing X/R ratios
Overshoot of overcurrent elements
Disengagement time
P747-TM-EN-1
P747-TM-EN-1.1
Chapter 16 - Technical Specifications
Measured
Setting +/-5%, or 20 mA, whichever is greater
> 0.95 x setting +/-5% or 20 mA, whichever is greater
1.05 × Setting +/-5% or 10 mA, whichever is greater
+/-5% or 40 ms, whichever is greater (under reference
conditions)
+/-5% or 40 ms, whichever is greater
+/-2% or 50 ms, whichever is greater
+/-2% or 50 ms, whichever is greater
Derived
1.05 × Setting +/-5%
Setting +/-5%
0.95 x setting +/-5%
+/-5% or 40 ms, whichever is greater
+/-2% or 50 ms, whichever is greater
Setting +/-5%
<30 ms
Accuracy
+/-5% over the X/R ratio of 1 to 120
< 40 ms
< 30 ms
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