ABB RELION REF615R Technical Manual page 152

Section 4
Protection functions
146
GUID-FF99F2A3-811A-4DAD-85E0-23AEC4C57183-ANSI V1 EN
Figure 68: Single-phase ground fault, phase A
In an example case of a two-phase short-circuit failure where the fault is between phases
B and C, the angle difference is measured between the polarizing quantity V
operating quantity I - I
B C
GUID-7CBA5DD4-CABC-4365-A4E3-4B5F73527ECA-ANSI V1 EN
Figure 69: Two-phase short circuit, short circuit is between phases B and C
in the self-polarizing method.
1MRS240050-IB C
and
BC
REF615R
Technical Manual