The Siemens 5SU1153-1KV10 is an FI/LS protector — a combined RCD (residual current device) and MCB (miniature circuit breaker) in one 1+N-pole unit. It provides both earth-fault and overcurrent protection in a single DIN-rail module, saving a slot in the panel compared to separate devices. Rated at 10 A with a C-trip curve (magnetic release at 5–10× In), it handles motor-starting inrush and moderate inductive loads without nuisance tripping. Breaking capacity is 4.5 kA, which covers standard domestic and small commercial supply impedances. The 70 mm depth (D=70 mm) fits standard flush-mount consumer units.
Panel integration
The 1+N-pole format occupies two modular-width spaces (about 36 mm). Wire termination is via tunnel terminals; torque to the manufacturer's specification on the label.