ABB RED615 Technical Manual page 220

Section 4
Protection functions
214
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
GUID-C2EC2EF1-8A84-4A32-818C-6D7620EA9969 V1 EN
Figure 108: Two-phase short circuit, short circuit is between phases B and C
The equations are valid when network rotating direction is counter-
clockwise, that is, ABC. If the network rotating direction is
reversed, 180 degrees is added to the calculated angle difference.
This is done automatically with a system parameter Phase rotation.
and operating quantity I
1YHT530004D05 D
- I marked as φ.
B C
Technical Manual
615 series