The Siemens 5SU1336-6FP20 is a 3-pole RCBO (residual current circuit breaker with overcurrent protection) from the SENTRON family, combining a 20 A overcurrent trip (Type B characteristic) with a 30 mA residual-current device (Type A, instantaneous). Per the datasheet, it breaks fault currents up to 6 kA per EN 60898 and IEC 60947-2, which covers the majority of domestic and light commercial distribution boards where the prospective short-circuit current stays under that threshold.
Temperature derating and mounting
At 40 °C it derates to 19.5 A, at 50 °C to 18.9 A, and at 60 °C to 18.4 A. The unit mounts in any position and accepts supply from top or bottom, which simplifies busbar routing in a crowded enclosure. Occupies 3 modular-width units (54 mm) on a DIN rail, with a depth of 72 mm and an installation depth of 70 mm. The IP20 rating applies only when the distribution board is installed and conductors are connected — not a standalone outdoor rating.
The 4 kV surge voltage resistance (impulse withstand) covers typical mains transients.