What this FI/LS-protector is and what it does
The Siemens 5SU1356-0DV25 is a combined residual-current device and miniature circuit breaker (RCBO) — an FI/LS-protector in Siemens' 5SU series. It packs ground-fault and overcurrent protection into a single 1+N-pole unit, saving a DIN-rail slot over separate RCD + MCB. The Type AC designation means it detects sinusoidal AC residual currents only; for pulsed DC or mixed-frequency faults you would need Type A or F. Rated at 25 A with a B-curve trip characteristic, it is sized for resistive and light inductive loads in final subcircuits. Breaking capacity is 6 kA, which suits most domestic and light commercial installations where the prospective short-circuit current at the board stays under that threshold. The pig-tail connection (factory-fitted neutral tail) simplifies wiring in distribution boards that use a separate neutral busbar.
Lifecycle and sourcing reality
This part is sourced and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time.
Panel integration notes
Mounts on standard 35 mm DIN rail in the distribution board. The 70 mm depth (D=70mm) fits standard enclosures; check clearance if the board has a shallow cover or door-mounted equipment. The pig-tail neutral is factory-terminated — no field crimp required, but verify the tail length reaches the neutral busbar before tightening. 1+N-pole configuration: the switched phase and neutral are both disconnected on fault, meeting isolation requirements for single-phase final circuits. The neutral pole is not overload-protected (the B-curve thermal-magnetic element is on the phase side only).