The
Add-on Adjustable Earth Fault Protection (w/o 4th CT) is engineered to enhance the protection capabilities of
4-Pole Air Circuit Breakers by detecting earth faults through residual current sensing of the phase conductors.
Unlike traditional systems that require a separate neutral (4th) current transformer, this solution operates without a 4th CT, simplifying installation while maintaining reliable earth fault protection. The adjustable settings allow precise coordination with upstream and downstream protective devices, improving selectivity and reducing unnecessary tripping.
This add-on is ideal for industrial, commercial, and critical power applications where enhanced earth fault protection is required without increasing system complexity. It integrates seamlessly with compatible ACB electronic trip units and complies with international protection standards.