The Siemens 5SU1653-0KV32 is an FI/LS combination device — a residual-current circuit breaker (RCD) and miniature circuit breaker (MCB) in one 1+N-pole unit, saving a DIN-rail position over separate devices. The 300 mA IΔn (rated residual operating current) is the trip threshold for earth leakage — higher than the 30 mA used for personal shock protection, so this unit is sized for equipment and fire protection rather than direct human contact. The B-curve 32 A overcurrent characteristic trips instantaneously at 3–5× rated current (96–160 A), suited for resistive and moderate inductive loads like lighting banks and small motor circuits.
Integration notes
The 70 mm depth (D=70MM) is the dimension from the DIN-rail mounting surface to the front of the device — check enclosure depth clearance, especially in shallow gland-plate or back-panel layouts. Spring-cage or screw terminals accept 1.5–25 mm² conductors depending on the terminal design; verify the specific terminal range on the device label before terminating.