Siemens Siprotec 7UM612 - Page 362

A Appendix
362
7UM61 Manual
C53000-G1176-C127-3
Figure A-6 Busbar System with Low-Ohmic Earthing: CT connections to three voltage transformers (phase-to-
ground voltages) and in each case three current transformers – earth fault detection as differential current
measuring of two CT sets; detection of displacement voltage at broken delta winding (e–n) as an additional
criterion.
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