SPAS 120 C Directional Earth-Fault Relay User Manual

This document is a user manual and technical description for the ABB SPAS 120 C directional earth-fault relay, a member of the SPACOM product family. It details the relay's features, application in isolated neutral and impedance earthed networks, operation principles (including directional low-set and high-set earth-fault stages), configuration, technical data, and testing procedures.