GE 489

4-40 489 Generator Management Relay
GE Power Management
4.7 S6 VOLTAGE ELEMENTS 4 SETPOINT PROGRAMMING
4
former high-side phase-to-phase faults. The reach setting is the positive sequence impedance to be covered, per phase,
expressed in secondary ohms. The same transformation shown for the Loss of Excitation element can be used to calculate
the desired settings as functions of the primary-side impedances.
The elements have a basic operating time of 150 ms. A VT fuse failure could cause a maloperation of a distance element
unless the element is supervised by the VTFF element. In order to prevent nuisance tripping the elements require a mini-
mum phase current of 0.05 x CT.
Figure 4–8: DISTANCE ELEMENT SETUP