ABB MS165-42 Motor Protection Circuit Breaker

The ABB MS165-42 Manual Motor Starter Protector is a compact, thermal-magnetic motor protection circuit breaker that provides manual switching along with overload, short-circuit, and phase-loss protection for three‑phase motors. It fits a 55 mm‑wide frame with 3 poles and can mount on a 35 mm DIN rail or panel, offering an adjustable current range of 30–42 A (Ie 42 A) and a rated operational voltage up to 690 VAC / 250 VDC. Its motor rating (AC‑3) is 22 kW at 400 VAC (40 HP at 600 VAC), with a breaking capacity of 50 kA at 400 VAC, Ui of 1000 V, and IP20 protection. Key features include a built‑in disconnect, trip‑free mechanism, and a lockable rotary handle for reliability in motor control centers, conveyors, pumps, compressors, and other industrial machinery in automation, HVAC, water treatment, and process control environments. The 55 × 142.65 × 122.1 mm device is commonly used for replacement, retrofit, and expansion of motor control systems in industrial settings, and is listed as a suitable alternative to related devices such as ABB MS165‑50, Eaton PKZM4‑40, Schneider Electric GV7RS40, and Siemens 3RV2041 equivalents.