Siemens 5SJ4210-8HG42 Miniature Circuit Breaker

Siemens 5SJ4210-8HG42 is a 2-pole SENTRON miniature circuit breaker rated at 10 A with a D-trip characteristic for 480Y/277 V systems. This UL 489-compliant device provides overcurrent protection in commercial or industrial distribution, offering a breaking capacity of 10 kA at 277 V AC. The breaker features an insulation voltage (Ui) of 440 V and a maximum AC operating voltage of 277 V, aligning with typical 480Y/277V panel applications. Weighing approximately 0.338 kg, the unit is designed for reliable cycling, with a mechanical life rating around 10,000 operating cycles. The IP rating is IP20 with connected conductors and IP40 in the handle range, reflecting standard protection for a bare device during normal use. The model belongs to Siemens' SINOVA/SENTRON 5SJ family of miniature circuit breakers and is specified for UL 489 and 480Y/277V standards, ensuring compatibility with appropriate Siemens panels and other UL-listed architectures. For installations requiring a two-pole, 10 A circuit breaker at 277 V AC with a Type D trip curve and robust breaking capacity, the 5SJ4210-8HG42 provides precise, verifiable electrical protection and a compact form factor suitable for control panels and distribution boards.