The Siemens 5SU1153-6KV13 is a combined residual-current device and miniature circuit breaker (RCBO), designated FI/LS-protector Type A. It integrates 10mA earth-leakage detection with a 4.5kA short-circuit breaking capacity in a single 1+N-pole unit, B-curve at 13A. The 70mm depth fits standard distribution board cutouts.
The 10mA IΔn (rated residual operating current) makes this unit suitable for circuits requiring enhanced personnel protection — such as socket outlets in wet areas, medical rooms, or laboratory benches where a standard 30mA RCD would not trip fast enough on low-level leakage. Type A detection covers pulsating DC residual currents from rectifiers and switched-mode supplies, not just sinusoidal AC. The B-curve (13A rated current) means the magnetic trip operates between 3 and 5 times In (39–65A), suited for resistive and moderate inductive loads like lighting, small heaters, and control transformers — not high-inrush motor circuits where a C- or D-curve would be needed.