The Over Current SPAJ144 C-AA ABB is a sophisticated three-phase protection relay offering comprehensive overcurrent and earth-fault protection for power distribution systems. It features dual-stage phase protection with both low-set (definite time/IDMT) and high-set (instantaneous/definite time) units, along with corresponding earth-fault protection stages. This versatile relay incorporates built-in circuit-breaker failure protection and includes two heavy-duty plus four signal output relays with configurable routing through an output relay matrix. The SPAJ144 C-AA Combined Overcurrent and Earth-Fault Relay ABB forms part of ABB's SPACOM product family and Distribution Automation system, carrying CE certification for EMC compliance.

Designed for radial feeder protection in various earthing systems (solidly earthed, resistance or impedance earthed), the OVERCURRENT AND E/F RELAY  ABB SPAJ144C-AA provides selective short-circuit and earth-fault protection. Its advanced monitoring capabilities include local display of measured values, fault records, and setting parameters accessible through front-panel controls or remotely via serial interface. The relay's flexible protection characteristics make it suitable for diverse applications requiring single-, two-, or three-phase overcurrent protection beyond its primary feeder protection role.

The Earth-Fault Relay ABB SPAJ144C-AA features robust self-supervision systems that continuously monitor microprocessor operation and electronics health. Supported by powerful configuration software, it enables detailed parameterization, data recording, and event logging. As part of ABB's Distribution Automation concept, the ABB SPAJ144C-AA Combined Overcurrent and Earth-Fault Relay integrates seamlessly into comprehensive power management solutions, offering reliable performance in demanding electrical environments.

With its combination of protection functions, monitoring capabilities, and communication features, the ABB SPAJ144C-AA delivers reliable grid protection while simplifying maintenance through accessible diagnostics. The relay's fiber-optic bus compatibility and remote configuration options make it ideal for modern automated substations. Whether protecting industrial plants, utility networks, or commercial power systems, the ABB SPAJ144C-AA provides adaptable, high-performance protection with the reliability expected from ABB's protection relay portfolio.