The Siemens SENTRON 5SU1644-7RC32 is a 4-pole RCBO — a combined residual-current circuit breaker and overcurrent miniature circuit breaker in one 7-module-wide unit. It carries a 32 A rated current with a C tripping characteristic (magnetic release at 5–10× In, typical for motor and lighting circuits with moderate inrush), and a 300 mA Type A residual-current element that detects pulsating DC fault currents as well as sinusoidal AC. That Type A rating matters: it covers the rectified waveforms from single-phase power supplies and VFD front ends, which a plain AC-type RCD would miss.
Rated short-circuit capacity is 10 kA per EN 60898 and 15 kA per IEC 60947-2.
Occupies 7 modular width units (roughly 126 mm) on a DIN rail, with an installation depth of 70 mm. Mounting position is any orientation. Ambient range spans -40 °C to 75 °C, with max 95% humidity — wide enough for unheated enclosures or outdoor-adjacent cabinets.