ABB RELION 620 Series Technical Manual page 589

1MRS757644 F
620 series
Technical Manual
GUID-A96D78E5-0D17-4CE7-818F-6CB804C7078D V1 EN
Figure 301: Example for busbar differential protection
Bus data:
U 20 kV
n
I 2000 A
n
I 25 kA
kmax
10 feeders per protected zone including bus coupler and incomer.
CT data is assumed to be:
CT 2000/1 A
R 15.75 Ω
in
U 436 V
kn
I <7 mA (at U )
e kn
R 1Ω
m
Section 4
Protection functions
583