Alarm Indication - ABB RELION Series Technical Manual

Section 5
Protection related functions
5.4.4.4
500
• Immediately after the fault occurrence, the estimate is affected by initial fault
transients in voltages and currents.
• Approximately one fundamental cycle after the fault occurrence, the fault
distance estimate starts to approach the final value.
• Approximately two fundamental cycles after the fault occurrence, the stability
criterion for fault distance estimate is fulfilled and the TRIGG_OUT event is sent.
The recorded data values are stored at this moment.
GUID-2C1E2C55-B61A-4200-BC8E-0F6FC9036A56 V3 EN
Figure 260: The behavior of fault distance estimate in time

Alarm indication

SCEFRFLO contains an alarm output for the calculated fault distance. If the
calculated fault distance FLT_DISTANCE is between the settings Low alarm Dis
limit and High alarm Dis limit, the ALARM output is activated.
The ALARM output can be utilized, for example, in regions with waterways or other
places where knowledge of certain fault locations is of high importance.
1MRS758755 A
REC615 and RER615
Technical Manual