ABB RELION 620 Series Technical Manual page 227

1MAC504801-IB E
620 series ANSI
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.
If the current amplitude falls below one percent of the nominal current, the
direction enters the non-directional area.
Section 4
Protection functions
221