Siemens 5SN1340 is a 1-pole miniature circuit breaker rated for 40 A, designed to protect a single-phase circuit from overcurrent. The 5SN1340‑8F variant is specified for 220/380 V AC operation and uses a G-curve trip characteristic to provide fast short-circuit response while tolerating normal inrush currents. Used in distribution panels to guard branch circuits such as lighting and outlets, this compact device delivers reliable overcurrent protection for residential and light commercial installations.
