Siemens SIPROTEC User Manual

Functions
2.5 Distance Protection
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
125
Figure 2-44 Logic for a phase-to-phase measuring unit, shown by the example of the L1-L2 loop
Phase-to-Earth Loops
For the calculation of the phase-to-earth loop, for example during an L3-E short-circuit (Figure 2-45) it must be
noted that the impedance of the earth return path does not correspond to the impedance of the phase.
Figure 2-45 Single-phase earth fault, fault loop

Siemens SIPROTEC Specifications

General

Brand	Siemens
Model	SIPROTEC
Category	Protection Device
Language	English