ABB 615 series Technical Manual page 717

1MAC059074-MB A
615 series ANSI
Technical Manual
GUID-E7269B2F-83FE-4385-8374-8F8C06D4CC0B V1 EN
Figure 353: Short circuit current waveform, fault occurs at time 0 seconds (Current
setting limit is multiplied by the square root of 2)
The phase voltage in a three-phase short circuit when a fault occurs at time = 0 s is shown
in Figure 354. The voltage drop caused by a three-phase fault provides more time for
determining the fault by means of an underimpedance protection.
Section 4
Protection functions
711