Motor protection for the grease-and-grit route
The ABB 1SDA068112R1 is an XT4N 160 frame motor protection circuit breaker with a magnetic-only (MA) trip unit, set for 10 A full-load current. The adjustable instantaneous magnetic trip range (Im) goes from 50 to 100 A, so it handles motor inrush without nuisance tripping on start-up. Rated for 690 V at 50/60 Hz, this is a three-pole unit built for protecting induction motors in industrial environments — think pumps, conveyors, and fans out on the plant floor where heat, dust, and vibration are the real test.
The 160 A frame rating (Iu) means the physical breaker shell and contacts are sized for a 160 A maximum; you're using a small chunk of that capacity here, which gives thermal headroom in the enclosure. The MA trip unit means no thermal overload — it's strictly magnetic (short-circuit and start-up protection), so you must pair this breaker with a separate overload relay for running protection. The adjustable Im range (50 to 100 A) lets you dial in the magnetic pickup to ride through your motor's locked-rotor current without tripping, typically set at 8-12x the motor FLA for standard induction motors.