What it is and what the ratings mean
The Siemens 5SU1356-1DV40 is a combined residual current device and miniature circuit breaker (RCBO) — an FI/LS-protector — in a single 1+N-pole module. It pairs a Type AC residual-current element (30 mA trip threshold) with a C-curve overcurrent characteristic rated at 40 A, all in a 70 mm deep housing with a pigtail connection for the neutral. The 30 mA sensitivity covers personnel protection against direct contact (the standard for socket-outlet circuits in most residential and commercial installations per IEC 60364). The 6 kA breaking capacity at the rated voltage means it can safely interrupt a fault current up to 6 kA without welding its contacts — sufficient for final subcircuits in a TN or TT system where the prospective short-circuit current at the board is under that threshold. The C-curve (magnetic trip between 5× and 10× In) is sized for loads with moderate inrush, like small motor-driven appliances or groups of LED drivers.
Lifecycle and sourcing reality
For a BOM line that calls out this exact order code, the part is specified into the bill and can be sourced to order against an RFQ. Availability and current pricing are confirmed at quote time through independent distribution — no allocation risk flagged on this SKU at present.
Integration notes
The 70 mm depth (D=70MM) is a standard dimension for DIN-rail mounted RCBOs, so it fits alongside other modular devices in a consumer unit or sub-distribution board without protruding past the enclosure cover. The pigtail neutral connection means the installer routes the factory-attached neutral lead to the neutral busbar — no separate neutral link to wire inside the module itself.