Siemens SENTRON 5SU9326-1CN63 — RCBO, 63 A, 30 mA, C-Curve
The Siemens SENTRON 5SU9326-1CN63 is a 2-pole residual-current-operated circuit breaker (RCBO) combining overcurrent and earth-fault protection in a single 4-module-width unit. It carries a 63 A rated current at AC with a C tripping characteristic, a 30 mA residual current sensitivity, and a 6 kA breaking capacity per EN 60898 and IEC 60947-2. The 30 mA sensitivity means it protects against fatal electric shock from direct contact — the standard threshold for socket-outlet circuits in residential and commercial installations. The C-curve (5–10× In) handles inrush from motor loads, fluorescent lighting banks, and small transformers without nuisance tripping, while the 6 kA short-circuit capacity clears faults up to that level in a 230/400 V distribution board.
Thermal Derating and Installation Constraints
The 63 A rating holds at 30 °C ambient. At 40 °C the continuous current must be derated to 58.6 A; at 45 °C to 56.1 A; at 50 °C to 54.8 A; and at 55 °C to 53.6 A. This derating curve governs the real load an RCBO can carry in a closed distribution board — an unventilated enclosure at 45 °C knocks nearly 7 A off the headline figure. Mounting position is unrestricted (any orientation), and the device occupies 4 modular width units (72 mm) on a standard DIN rail. Depth is 77 mm, installation depth 70 mm. Supply can enter from top or bottom. The IP20 rating applies only when installed in a distribution board with conductors connected — the RCBO itself is not a standalone outdoor device.
Regulatory and Compliance Profile
The device is designed to EN 60898 and IEC 60947-2, carrying a 6 kA breaking capacity under both standards. Overvoltage category III (distribution level), pollution degree 2. The insulation voltage is rated 264 V. It is halogen-free and silicon-free. Touch protection is provided. Energy limitation class 3. The residual current type is AC (sinusoidal AC fault currents only). The product designation per IEC 81346-2 and DIN EN 61346-2 is F (protective device).