The Siemens 5SU1356-0KV06 is a combined residual-current and miniature circuit breaker (RCBO) — an FI/LS protector in Siemens' 5SU1 line. It packs a Type AC residual-current device with 30 mA sensitivity and a 6 kA breaking-capacity B-curve 6 A overcurrent trip into a single 1+N-pole module.
In a domestic or light commercial installation with a typical upstream fuse or MCB rated at 6 kA or less, this coordinates without requiring a current-limiting backup. The 1+N-pole construction switches both phase and neutral, but the neutral pole is a switching neutral only — it does not provide overcurrent protection on the neutral conductor. The 6 A rated current (In) limits the protected circuit to a 6 A continuous load, typical for a lighting sub-circuit or a single socket outlet.