ABB REJ603BBB10NN3XC Self-Powered Feeder Protection Relay

Description

ABB REJ603BBB10NN3XC Self-Powered Feeder Protection Relay is a self-powered digital relay designed for secondary distribution networks, with primary applications in ring main units for distribution grids, as well as selective short-circuit and earth fault protection for feeders, plus transformer protection in utility and industrial sectors. A key highlight is its self-powering design, which draws operating power directly from current transformers instead of requiring an external auxiliary power supply, making it ideal for remote locations without access to auxiliary power.

This relay offers self-powered three-phase non-directional overcurrent and earth fault protection with both DMT and IDMT characteristics, and integrates IEC and special IDMT curves to meet time coordination requirements for secondary distribution protection. It features dual earth fault measurement modes, supporting internal vector summation or input from an external CBCT. Additional critical functions include protection blocking via second harmonic measurement to ensure stability during transformer magnetic inrush, a capacitor discharge pulse output for low-energy trip coils, and a built-in manually resettable electromechanical flag for trip indication. Configuration is simplified via DIP switches, which are protected by a transparent cover.