2.4 Distance protection Z<
VAMP 24h support phone +358 (0)20 753 3264
Fault too far away from the protected 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 U
0
_I
0
is selected).
Selected relay sees the fault but outside the zone Z1e< so there
is no reason to trip.
To Next Page
Loading...