SPAJ 144 C Combined Overcurrent and Earth-Fault Relay User Manual

This document is a user manual and technical description for the SPAJ 144 C combined overcurrent and earth-fault relay, detailing its features, operation, and configuration. It covers protection stages including low-set, high-set, and superhigh-set phase overcurrent units, earth-fault units, phase discontinuity, and circuit breaker failure protection, along with output relay matrix, self-supervision, and serial interface capabilities.