ABB RER620, Technical Manual

Page: 166 / 584

Section 4
1MAC309294-MB F
Protection functions
160 RER620
Technical Manual
• The Max forward angle and Max reverse angle settings are not settable, but have a
fixed value of 88 degrees
• The sector limits of the fixed sectors are rounded.
Sector rounding in the phase angle classic 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 1...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.
Figure 72: Operating characteristic for phase angle classic 88
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.
RCA
Non-operating area
Max forward angle
Min forward angle
Min reverse angle
88 deg
20% nominal
amplitude
100% nominal
amplitude
1% nominal
amplitude
Max reverse angle
88 deg
0
I
0
-V