Siemens 5SU9356-1CN63 — RCBO for 63 A final circuits
The Siemens 5SU9356-1CN63 is a 2-pole residual-current-operated circuit breaker (RCBO) from the SENTRON series, combining overcurrent and earth-fault protection in a single 36 mm-wide (2 MW) DIN-rail module.
At 40 °C it derates 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 — a 15 % drop from the 30 °C figure.
Residual current type and design
The residual-current element is Type AC — it detects sinusoidal AC earth-fault currents only. The design is instantaneous (no intentional time delay), so it trips within the standard RCD response time on a 30 mA fault. This is suitable for general socket-outlet protection but not for selectivity with upstream delayed RCDs.