GE Industrial Solutions Entellisys 5.0 User Manual - Manual (Page 68)

Single-point functions 68
5
Figure 5-4 Ground Fault settings screen
5.1.3.4 Usage
The GF Protection function detects unintentional current flowing from a circuit to a conducting
path to ground. These currents are usually of a lower magnitude than the current set by the LT
pickup setting and would not normally be sensed by that protection function. GF protection is
performed by calculating the vector sum of the three phase currents in a three-wire system or
the vector sum of the three phase currents and the neutral in a four-wire, wye-system and
comparing this sum to a pickup threshold.
GF pickup, trip, and dropout events are recorded for GF alarms and trip events in the Entellisys
Sequence of Events log. Waveforms and fault reports are captured on a GF trip or alarm event,
and can be viewed from the Sequence of Events log.