Siemens 5SY4140-5 1-Pole 40 Amp Circuit Breaker

Siemens 5SY4140-5 is a UL 1077-listed, single-pole miniature circuit breaker from the Sentron 5SY4 family, rated for 40 A at 230/400 V AC and suitable for 50/60 Hz systems. Designed for DIN-rail panel installations, it mounts on standard 35 mm DIN rails and is commonly used to provide additional protection on a branch circuit alongside a main protective device in control panels and distribution boards. This 1-pole unit features a type A (low inrush) trip curve, making it appropriate for circuits with moderate inrush currents such as certain motors or transformers, and it employs thermal/magnetic trip protection for reliable response to both overloads and short circuits. As a compact supplementary protector, the 5SY4140-5 is intended to be used indoors within low-voltage applications, enabling targeted protection for individual loads while remaining compatible with other Sentron components on the same DIN rail.