This is a rectangular sensor for earth leakage protection for Compact NS 630b to 1600 devices equipped with Micrologic 7 A/P trip unit. The sensor is installed around the busbars (phases + neutral) to detect the zero phase sequence current required for the earth-leakage protection. The operational current is up to 1600 A. The inside dimensions are 280mm (W) x 115mm (H) x 71mm (D). The external dimensions are 381mm (W) x 233mm (H) x 71mm (D). The weight is 14 Kg. The sensor is installed in the switchboard. The sensor is provided with a cable for the connection to Compact NS circuit breaker.