What it is and what it does
The Siemens 5SU1356-1KV32 is a combined residual-current device and miniature circuit breaker (RCD/MCB) — an FI/LS protector in Siemens' 5SU1 series. It integrates Type AC earth-leakage detection (30 mA trip threshold) with a 6 kA breaking-capacity MCB on the same 1+N-Pole DIN-rail footprint. The C 32 A thermal-magnetic characteristic means it handles inrush from motor or lighting loads up to 32 A while tripping instantaneously on short circuits. This single-module unit saves a DIN position compared to separate RCD + MCB.
Deployment context
Snap-on mounting to a 35 mm DIN rail per EN 60715. The 70 mm depth (D=70MM) fits standard distribution boards and sub-distribution panels. Type AC detection covers sinusoidal AC residual currents — the common fault type in residential and light commercial final circuits. The 6 kA breaking capacity is sized for domestic and small commercial installations where the prospective short-circuit current at the board does not exceed 6 kA.