The Siemens 5SM2345-6KK01 is a SENTRON RCD-unit designed as a 4-pole residual current device with a 63 A rated current at AC and a 30 mA Type A trip threshold. It is short-time delayed, making it suitable for systems where nuisance tripping from transient surges or inrush currents needs to be avoided. This unit is intended for use with the 5SY series miniature circuit breakers, forming a combined RCBO assembly in a distribution board.
The 63 A rating at AC governs the maximum continuous load current the RCD can carry without overheating. This is the headline figure for sizing against the downstream load. The 30 mA rated fault current is the standard threshold for personal protection against electric shock in most residential and commercial installations — it will trip within the required time on a ground fault exceeding 30 mA. The short-time delayed design provides immunity to brief voltage transients and inrush currents that would otherwise cause a nuisance trip. This is a deliberate choice for circuits with capacitive or inductive loads — think motor starters, UPS inputs, or LED lighting banks — where the initial current spike exceeds 30 mA for a few milliseconds but is not a genuine fault. Temperature derating is documented across the operating range: 58.6 A at 40 °C, stepping down to 50.4 A at 70 °C (–). If the distribution board runs hot — say, above 45 °C — the effective current capacity drops below the nominal 63 A. An MRO planner or panel builder must check the ambient temperature inside the enclosure and apply the corresponding derated figure to avoid nuisance tripping or thermal damage.
Installation depth is 70 mm. It mounts in any position and the power supply connection can be made from the top or bottom. The fastening method is REG, standard for DIN-rail components.
The reference code according to IEC 81346-2 is F. The overvoltage category is III, suitable for fixed installations in distribution boards. The degree of pollution is 2, covering normal indoor environments with only non-conductive pollution. Surge current withstand is rated at 3 kA, and surge voltage withstand at 4 kV. The operating frequency range is 50/60 Hz. The unit is not sealable and the OFF-delay time is not adjustable. The rated fault current is also not adjustable. A protection function against false tripping is included. The minimum test voltage is 195 V.