3U
0
UL1
IEC07000190-2-en.vsd
IEC07000190 V2 EN-US
Figure 49: Earth fault in Non-effectively earthed systems
8.3.3.5 Direct earthed system
GUID-EA622F55-7978-4D1C-9AF7-2BAB5628070A v8
In direct earthed systems, an earth fault on one phase is indicated by voltage
collapse in that phase. The other healthy phase will still have normal phase-to-earth
voltage. The residual sum will have the same value as the remaining phase-to-earth
voltage, which is shown in Figure 50.
IEC07000189 V2 EN-US
Figure 50: Earth fault in Direct earthed system
1MRK 505 388-UEN B Section 8
Voltage protection
Busbar protection REB650 2.2 IEC 141
Application manual