ABB RELION REX640 Technical Manual page 428

Section 4
Protection functions
422
GUID-A56EF42C-BADA-4E3B-9E82-3ACB1F5514F3 V1 EN
Figure 224: Definition of the relay characteristic angle, RCA=+60 degrees in a
solidly earthed network
Example 3
The "Phase angle" mode is selected, isolated network (φRCA = -90 deg)
=> Characteristic angle = -90 deg
1MRS759142 C
REX640
Technical Manual