ABB RELION REX640 Technical Manual page 468

Protection functions
Figure 263: Operating characteristic Iosin(φ) in forward fault
The operating sector is limited by angle correction, that is, the operating sector is
180 degrees - 2*(angle correction).
Example 2.
Iosin(φ) criterion selected, reverse-type fault
=> FAULT_DIR = 2
Figure 264: Operating characteristic Iosin(φ) in reverse fault
468
1MRS759142 F
REX640
Technical Manual