Siemens 5SY42-C40 Circuit Breaker 2 Pole 40A 400VAC

Siemens 5SY42-C40 is a two-pole miniature circuit breaker rated for 40 A at 400 VAC, designed to protect distribution circuits in industrial and commercial panels. It belongs to the SENTRON 5SY family, delivering reliable overcurrent protection for multi‑wire circuits in standard 50/60 Hz networks. This unit includes a 5ST3010 auxiliary switch, providing a 1 normally open and 1 normally closed contact for status indication or interlocking with control logic. The 5ST3010 auxiliary switch is rated for operation at 400/230 VAC, ensuring compatibility with typical panel mains and automation circuits. Ideal for machine control panels, distribution boards, and automation subsystems that require a 40 A protective device on 400 V systems, the 5SY42-C40 supports straightforward integration with other Siemens miniature breakers in the 5SL/5SY/5SP family and compatible accessories, enabling coordinated protection and simple field installation in industrial environments.