What it is and what it does
The Siemens 5SU1653-1KV13 is an FI/LS protector — a combined residual-current device (RCD) and miniature circuit breaker (MCB) in one DIN-rail module. It saves a panel row by collapsing two protective functions into a single 1+N-POL unit. Type AC detection means it trips on sinusoidal AC residual currents only — the standard choice for general-purpose circuits without electronic loads or variable-speed drives that generate pulsed DC fault currents. Rated residual current IΔn 300 mA and breaking capacity 4.5 kA. The C-curve 13 A thermal-magnetic characteristic handles moderate inrush from small motors or lighting ballasts without nuisance tripping.
Panel fit and deployment
Snap-on DIN-rail mount, 70 mm deep. Occupies one modular width for the 1+N-POL configuration. Wire-up is standard: line in top, load out bottom, neutral busbar on the N side. Rated for 50/60 Hz supply networks. Use in residential or light commercial distribution boards where Type AC RCD protection is accepted by local wiring rules.