Direct Grounded System - ABB REB670 Applications Manual

1MRK 505 370-UUS A
8.3.3.5
Busbar protection REB670 2.2 ANSI
Application manual
ANSI07000190-1-en.vsd
ANSI07000190 V1 EN-US
Figure 110: Ground fault in Non-effectively grounded systems

Direct grounded system

In direct grounded systems, an ground fault on one phase is indicated by voltage
collapse in that phase. The other healthy phase will still have normal phase-to-ground
voltage. The residual sum will have the same value as the remaining phase-to-ground
voltage, which is shown in Figure 111.
ANSI07000189 V1 EN-US
Figure 111: Ground fault in Direct grounded system
ANSI07000189-1-en.vsd
Section 8
Voltage protection
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