The Siemens 5SU1356-0KV16 is a combined residual-current device and miniature circuit breaker (RCD/MCB) — an FI/LS protector — in a single 1+N-pole module. It integrates Type AC earth-leakage detection at 30 mA with a B-curve overcurrent trip rated 16 A, all within a 70 mm wide housing. The 6 kA breaking capacity covers the majority of domestic and light commercial sub-distribution boards where the prospective short-circuit current stays under that threshold.
What the ratings mean for fit
The 30 mA residual sensitivity (IΔn) is the standard for personal protection against direct contact in TN and TT systems per IEC 60364. Type AC detection means it responds to sinusoidal AC fault currents only — not pulsed DC or smooth DC, so it is not suitable for circuits with variable-speed drives, LED drivers, or other power-electronics loads that can generate non-sinusoidal leakage. The B-curve (16 A rated current) trips between 3 and 5 times In for short-circuit protection, which is the standard choice for resistive and general-purpose loads with moderate inrush — socket outlets, lighting circuits, small appliances. The 6 kA rated short-circuit capacity (Icn) per EN 61009-1 is the entry-level breaking capacity for domestic final circuits; verify the prospective fault current at the installation point does not exceed this value.
Panel integration notes
The 70 mm width (D=70MM) means this unit occupies 4 standard 17.5 mm DIN-rail modules. It snaps onto a 35 mm DIN rail per EN 60715. The 1+N-pole configuration switches the phase conductor and provides a switched neutral — the neutral pole is not protected against overcurrent but is disconnected when the device trips. Verify the neutral bar arrangement in the distribution board: this unit requires a dedicated neutral connection that passes through the residual-current summation transformer.