ABB RELION 620 Series Technical Manual page 465

1MAC504801-IB E
620 series ANSI
Technical Manual
ID_COSPHI/ In
1.5
1.0
Trip value
0.5
0.0
0.0 1.0
GUID-9D592151-7598-479B-9285-7FB7C09F0FAB-ANSI V1 EN
Figure 210: Operating characteristics of the stabilized ground-fault protection
function
GUID-4BF3E289-E355-4C31-B87E-151DFDDCEBA8-ANSI V1 EN
Figure 211: Setting range of the operating characteristics for the stabilized differential
current principle of the ground-fault protection function
The Trip value setting is used for defining the characteristics of the function. The
differential current value required for tripping is constant at the stabilizing current values
0.0 < IB/In < 1.0, where In is the nominal current, and the In in this context refers to the
nominal of the phase current inputs. When the stabilizing current is higher than 1.0, the
slope of the operation characteristic (ID/IB) is constant at 50 percent. Different operating
characteristics are possible based on the Trip value setting.
TRIPPING
IB
NON TRIPPING
ID
3.0
2.0
Section 4
Protection functions
IB/In
459