The Siemens 5SU1356-1KK13 is a SENTRON RCBO — a combined overcurrent and residual current device in one 2-module-wide (36 mm) package. It protects a single-phase final circuit: one pole switched and protected (1P+N), neutral switched but not protected. The 30 mA residual current element catches earth faults at the sensitivity level required for personal protection in most residential and light commercial installations. Rated 13 A at AC (30 °C ambient), the device derates linearly as panel temperature rises — at 40 °C it carries 12.48 A, at 50 °C it carries 11.96 A, and at 70 °C it drops to 10.01 A. This derating curve matters when the RCBO sits in a densely populated enclosure with limited airflow; the 13 A nameplate is only valid at the reference ambient. The residual current type is AC — it detects sinusoidal AC earth fault currents only. For circuits with pulsed DC or smooth DC fault components (variable-speed drives, LED drivers, EV chargers), an A or F type RCBO would be required instead. This part is for straightforward AC loads without rectification or switching power supplies in the protected circuit.
Supply can enter from top or bottom — no orientation restriction. IP20 applies only when the distribution board is installed and conductors are connected; the RCBO itself is not sealed for wet locations.