ABB RED615 Technical Manual page 194

Section 4
Protection functions
188
GUID-C2EC2EF1-8A84-4A32-818C-6D7620EA9969 V1 EN
Figure 92: 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.
Negative sequence voltage as polarizing quantity
When the negative voltage is used as the polarizing quantity, the angle difference
between the operating and polarizing quantity is calculated with the same formula
for all fault types:
ANGLE X _ = ( − U ) −
ϕ ϕ
2
GUID-470263DD-C1D7-4E59-B011-24D8D35BD52A V3 EN
( ) I −
ϕ
2 RCA
1YHT530004D05 D
(Equation 1)
615 series
Technical Manual