The Siemens 5SU1154-7KV10 is a combined residual-current device and miniature circuit breaker (RCBO) — an FI/LS protector — in a single 1+N-pole module. It integrates Type A earth-leakage detection at 10 mA IΔn with a C-curve overcurrent trip at 10 A, all in a 70 mm wide housing rated for 10 kA breaking capacity. That 10 mA sensitivity is the key spec: it catches leakage currents well below the 30 mA threshold used for general socket-outlet protection, making this unit suited for circuits where a lower touch-voltage or equipment-protection threshold is required.
Deployment context
The 70 mm width (4.5 modules on a standard DIN rail) means it occupies more space than a typical 1+N RCBO in a 36 mm package — factor that into panel fill calculations, especially in retrofit or high-density sub-distribution boards. The Type A designation means it detects pulsating DC residual currents (typical from rectifier circuits, switching power supplies, or variable-speed drives) in addition to sinusoidal AC faults, so it is suited for modern mixed-load panels where electronics are present.