What it is and what the ratings mean
The Siemens 5SU1356-0DA32 is a combined residual-current device and miniature circuit breaker (RCD/MCB, also known as an FI/LS protector) in a single 1+N-pole unit. It is rated Type AC (suitable for sinusoidal AC fault currents), with a rated residual operating current IΔn of 30 mA — the standard for personal protection against direct contact. The thermal-magnetic release follows a B-curve characteristic, tripping at 3–5× rated current, and the unit is rated for 32 A continuous load. Breaking capacity is 6 kA per IEC 60898, sufficient for most residential and light commercial sub-distribution boards where the prospective short-circuit current stays under that threshold.
Deployment context and integration
This FI/LS protector snaps onto a DIN rail in a distribution board or sub-panel. The pigtail connection on the neutral side simplifies wiring in pre-assembled consumer units. The 70 mm depth (D=70 mm) is standard for Siemens 5SU series devices, so it fits existing enclosures without extra gland-plate clearance. Type AC detection means it is intended for circuits with sinusoidal residual currents — typical for general-purpose socket outlets, lighting, and resistive loads. It is not rated for pulsating DC or smooth DC fault currents (those call for Type A or Type F devices).