The Siemens SENTRON 5SV9316-1NK25 is a combined residual-current-operated circuit breaker (RCBO) that packs overcurrent and earth-fault protection into a single 18 mm module. It is rated 25 A operational current with a 30 mA residual fault trip threshold, Type AC (sinusoidal AC residual currents only), C-curve magnetic release, 1P+N (switched neutral), and a 6 kA breaking capacity certified to both EN 60898 and IEC 60947-2.
At 25 A and C-curve, this RCBO is sized for general-purpose final circuits with moderate inrush — lighting, socket outlets, small appliances — not motor or transformer loads where a D-curve would be needed. The 6 kA breaking capacity (Icn = 6 kA per EN 60898, Icu = 6 kA per IEC 60947-2) is adequate for most domestic and light commercial installations where the prospective short-circuit current at the point of installation is below 6 kA. In industrial panels with higher fault levels, a current-limiting upstream MCCB or fuse would be required for coordination. The 18 mm width (1 modular unit) and 77 mm depth let it fit standard DIN-rail enclosures without crowding adjacent devices. Mounting position is unrestricted. The IP20 rating applies only when the distribution board is installed with connected conductors — this is a panel-internal device, not a field-mounted unit.
The product carries an overvoltage category III rating (fixed installation, not plug-connected equipment) and pollution degree 2 (non-conductive dust, occasional condensation). These are standard for residential and commercial panelboard components.