ABB REF 610 Technical Reference Manual page 43

1MRS755310
Feeder Protection Relay
Technical Reference Manual
The time/current curve groups based on the IEC standard are illustrated in
Fig. 5.1.4.9.-1...Fig. 5.1.4.9.-4.
If the ratio between the current and the set start value is higher than 20,
the operate time is the same as when the ratio is 20.
REF 610 REF 610
43