Panel fit and selectivity
The Siemens 5SV3646-8KL is a 4-pole SENTRON RCCB rated 63 A at 40 °C through 55 °C, with a 300 mA Type A residual current trip and a selective (time-delayed) characteristic. The selective design means it withstands a 5 kA surge current without tripping, coordinating downstream with standard RCCBs so only the faulted branch clears. This avoids nuisance blackouts on the main incomer when a downstream device sees a transient earth fault.
At 65 °C it derates to 57.35 A, and at 70 °C to 48.8 A. The maximum permissible ambient for storage is 75 °C, with a minimum of -40 °C. Operating frequency is 50/60 Hz, and the supply frequency is rated at 50 Hz. The short-circuit current rating is 10 kA per IEC 61008-1, with an I²t withstand of 110 000 A²·s and a let-through current of 7 100 kA.
The part is silicon-free, which matters for paint-shop or potting applications where silicone outgassing causes adhesion failure.
Installation and approvals
Mounts on DIN rail (REG) in any position. Overvoltage category III, IP20 protection (with connected conductors in an installed distribution board). The test button requires a minimum 100 V supply. Approvals include EN 60898 (rated 0.8 kA) and IEC 61008-1 (rated 0.8 kA). The Type A residual current detection handles AC sinusoidal and pulsating DC fault currents — the standard choice for circuits with rectified loads like switching power supplies or variable-speed drives.