Application Guide - NP900 Series
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A996A
Figure 3.2.6-44 Undercompensated medium size network intermittent earth fault seen by
faulty feeder relay.
Figure 3.2.6-45 Undercompensated medium size network intermittent earth fault seen by
healthy feeder relay.
As can be seen from the figures the residual voltage in both cases is high. When
considering the normal directional earth fault protection in the close to resonance case