ABB RET670 - Page 530

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ANSI07000190-1-en.vsd
ANSI07000190 V1 EN
Figure 215: Ground fault in Non-effectively grounded systems
Direct grounded system
In direct grounded systems, an ground fault on one phase indicates a voltage collapse
in that phase. The two healthy phases will have normal phase-to-ground voltages. The
residual sum will have the same value as the remaining phase-to-ground voltage. See
figure
216.
Section 3 1MRK504116-UUS C
IED application
524
Application manual