ABB RED615 Technical Manual page 193

1YHT530004D05 D
615 series
Technical Manual
the faulted phase is phase A. The polarizing quantity is rotated with 90 degrees.
The characteristic angle is assumed to be ~ 0 degrees.
GUID-6C7D1317-89C4-44BE-A1EB-69BC75863474 V1 EN
Figure 91: Single-phase earth fault, phase A
In an example of the phasors in a two-phase short-circuit failure where the fault is
between the phases B and C, the angle difference is measured between the
polarizing quantity U
AB
and operating quantity I
Section 4
Protection functions
- I marked as φ.
B C
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