The Siemens 5SM1616-8 is a 2-pole SENTRON residual current circuit breaker (RCCB) rated 63 A at 230 V AC, 50 Hz, with a 300 mA type A tripping characteristic. It's a selective (time-delayed) device, meaning it coordinates with downstream RCCBs to isolate only the faulted branch — a key feature for panel builders who need to keep the rest of the line running during a ground fault.
The 63 A rating holds at 40 °C and 45 °C; above that it derates to 60.48 A at 50 °C, down to 50.4 A at 70 °C. Type A detection catches both sinusoidal AC residual currents and pulsed DC (from rectifiers, VFDs, or switching supplies). The 300 mA threshold is typical for fire-protection or selective main-switch applications — not for personnel protection, which needs 30 mA or lower. Conductor range is 1 mm² minimum to 16 mm² maximum — covers everything from a 1.5 mm² lighting circuit to a 10 mm² feeder.
Mounting position is any — no top/bottom restriction for the line/load connection. IP20 with conductors connected; suitable for enclosed distribution boards only.