ABB RELION 620 Series Technical Manual page 399

1MRS757644 F
620 series
Technical Manual
Phase angle 88 implements the same functionality as the phase angle but with the
following differences:
• The Max forward angle and Max reverse angle settings cannot be set but they
have a fixed value of 88 degrees
• The sector limits of the fixed sectors are rounded.
Sector rounding in the phase angle 88 consists of three parts:
• If the current amplitude is between 1...20 percent of the nominal current, the
sector limit increases linearly from 73 degrees to 85 degrees
• If the current amplitude is between 20...100 percent of the nominal current, the
sector limit increases linearly from 85 degrees to 88 degrees
• If the current amplitude is more than 100 percent of the nominal current, the
sector limit is 88 degrees.
There is no sector rounding on the other side of the sector.
GUID-0F0560B7-943E-4CED-A4B8-A561BAE08956 V2 EN
Figure 193: Operating characteristic for phase angle 88
Section 4
Protection functions
393