RCCB for 230 V AC sub-distribution
The Siemens 5SM1617-0 is a 2-pole residual current operated circuit breaker (RCCB) from the SENTRON 5SM1 series, rated 80 A at 230 V AC with a 300 mA trip threshold, Type AC (sinusoidal AC fault currents only). It carries a 10 kA short-circuit current rating (SCCR). The 80 A rating holds at 40 °C and 45 °C; above that, derate linearly to 64 A at 70 °C — a curve worth checking if the RCCB sits in a warm enclosure or next to heat-generating contactors.
Wire terminals accept 1 to 16 mm² solid or stranded, torqued to 2.5–3 N·m. Supply can land top or bottom — no mandatory orientation.
It remains a standard catalog item in the SENTRON 5SM1 family.