The Siemens 5SJ6213-6 is a 2-pole miniature circuit breaker from the SENTRON 5SJ6 family, rated 13 A at 400 V AC with a B tripping characteristic. Two poles give you simultaneous disconnection of both phase conductors in a single-phase or split-phase circuit.
Snaps onto standard DIN rail. At 2 width units (roughly 36 mm) it consumes minimal rail space.
Electrical coordination
Insulation voltage rated 440 V AC, with multi-phase operation maximum also 440 V — so it's suited for 400 V three-phase systems with some headroom. Overvoltage category III means it's designed for fixed-installation distribution boards, not for equipment-level protection. DC rating is 60 V maximum, so it can also serve in DC sub-circuits like control power supplies or battery banks up to that voltage. Energy limiting class 3 provides good current limitation under short-circuit conditions, reducing let-through energy to downstream components.