What this RCBO delivers
The Siemens 5SU1654-7KK06 is a 2-pole RCBO from the SENTRON family, combining overcurrent protection and residual current detection in a single 36 mm wide module (2 MW). Rated 6 A with a Type C tripping characteristic, it handles the inrush of small motor and lighting loads on a 50 Hz supply. The Type A residual current element catches pulsating DC fault currents — the kind rectified loads or variable-speed drives can produce — so it suits mixed-load final subcircuits where pure AC detection would miss a fault. Breaking capacity is 10 kA per EN 60898 for domestic-grade duty and 35 kA per IEC 60947-2 for industrial panel coordination — the higher figure means it can be installed downstream of a high-capacity transformer without needing an upstream current-limiting fuse for the fault level. Overvoltage Category III and Pollution Degree 2 confirm it is rated for fixed-installation sub-distribution boards, not portable equipment.
Thermal derating — what the 6 A rating means at panel ambient
The 6 A nominal rating is at 30 °C. Inside a closed panel at 40 °C the continuous current drops to 5.7 A; at 50 °C it is 5.4 A; at 60 °C it is 5.1 A. If the panel ambient hits 70 °C the usable rating is 4.62 A. For a panel OEM wireman sizing the branch circuit, the 40 °C figure is the practical design limit unless the enclosure is ventilated. The mounting position is unrestricted, and supply can enter from either top or bottom — no orientation constraint during installation.
Physical fit and environmental limits
The module is 36 mm wide (2 modular width units), 90 mm tall, and 77 mm deep with an installation depth of 70 mm. IP20 rating applies once the distribution board is closed and conductors are connected — this is a panel-internal device, not surface-mount. Halogen-free and silicon-free construction matters for clean-room or high-reliability environments where outgassing can contaminate contacts or optics. Operating temperature range is -40 °C to 75 °C, covering unheated enclosures and hot panel interiors alike.