FI/LS switches (RCBOs) provide personal and property protection as well as protection against electrically ignited fires in accordance with DIN VDE 0100-410 and DIN VDE 0100-530. They ensure the protection of single-phase circuits against overload and short-circuit currents, protection against sinusoidal alternating currents and pulsating currents with smooth residual direct current of up to 6 mA to ground. Additionally, they offer fault protection (protection against indirect contact), additional protection (with IΔn ≤ 30 mA), and fire protection (with I∆n ≤ 300 mA). They comply with the product standard IEC/EN 61009-1 (VDE 0664-20). The connection is made directly via the Smissline TP socket system, and the external conductor connection can be freely chosen for single-phase devices (L1, L2, or L3).