2.4 Distance protection Z<
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Fault L2-G inside zone Z1e<
Fault is noticed since one of the voltages in the network area is
dropped below the set ―Phase under-voltage limit‖ limit and
two other voltages are increasing above the set ―Phase over-
voltage limit‖ limit. This phase has to last least 100ms.
When second fault appears another voltage has to drop at least
10% below the healthy phase‖. Also set amount of zero
sequence voltage has to be exceeded (same applies to residual
current if triggering condition U0_I0 is selected).
Selected relay sees the fault 2 (L2-G) inside the zone Z1e<. If
phase priority is selected as ―1-> 2-> 3‖ this relay would NOT
trip because fault L2-G inside the zone does not have the
highest priority at the moment when the double earth-fault
occurs.
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