FI/LS-Protector for Combined Earth-Leakage and Overcurrent Protection
The Siemens 5SU1354-0KV13 is a Type AC FI/LS-protector (RCD/MCB combo) in a 1+N-pole form factor, rated at 13 A with B-curve tripping and a 30 mA residual-current sensitivity. The 10 kA breaking capacity suits it for final subcircuits in TN and TT systems where fault levels stay under that threshold. The 70 mm width means it occupies two standard modular DIN-rail positions in a distribution board.
The B-curve characteristic (13 A) means the magnetic trip operates at 3 to 5 times rated current — typically 39 to 65 A — so it clears short-circuits fast enough for cable protection in residential and light commercial final circuits, but avoids nuisance tripping on modest inrush from lighting or small motors. Type AC detection covers sinusoidal AC residual currents only — not pulsed DC or smooth DC, so it is not suitable for circuits with variable-speed drives, LED dimmers, or EV chargers that generate non-sinusoidal leakage. The 10 kA Icn (rated short-circuit capacity) is the fault current the device can interrupt once under standard test conditions; coordination with an upstream 63 A gG fuse or MCB is required when prospective fault current exceeds 10 kA.
The 70 mm width (two modular DIN positions) and 1+N-pole layout — switching the line conductor only, with the neutral solidly connected — match the standard Siemens 5SU1 series footprint. The neutral terminal is on the right side; incoming line connects to the top-left terminal, outgoing to the bottom-left. No neutral wire needs to pass through a separate N busbar link, which simplifies wiring in a distribution board where the neutral is already commoned.