The Siemens SENTRON 5SU1624-6KK82 is a 2-pole RCBO (residual current circuit breaker with overcurrent protection) rated 125 A at 230/400 V AC, 50 Hz. It combines a Type A residual current device (300 mA sensitivity) with a B-curve miniature circuit breaker into a single 7-module-width unit. The 10 kA breaking capacity per EN 60898 and IEC 60947-2 means it can safely interrupt fault currents up to that level on a 230/400 V supply — enough for most residential and light commercial distribution boards where the prospective short-circuit current is known to stay under that threshold.
The Type A RCD detects pulsating DC residual currents in addition to sinusoidal AC, which covers modern electronics and single-phase rectified loads. At 125 A, this is a high-current RCBO; most panelboards will need a 125 A busbar tap or a dedicated feed. The 7 MW (modular width units) means it occupies 7 x 18 mm = 126 mm on the DIN rail — plan the enclosure layout accordingly; a standard 12-module consumer unit won't fit this alongside many other ways.
Mounting and environment
The IP20 rating applies only when installed in a distribution board with conductors connected — this is a panel-mount device, not for standalone outdoor use. Mounting position is any orientation. The supply can enter from either top or bottom, which simplifies wiring in tight enclosures. Installation depth is 70 mm (unit depth 77 mm including the front projection).
Compliance and approvals
Insulation voltage (Ui) is 440 V; surge voltage resistance is 4 kV. Overvoltage category III, pollution degree 2 — standard for fixed-installation distribution boards. Halogen-free and silicon-free construction.