The Siemens 5SU1653-6KV06 is an FI/LS-Protector Type A (PSE/SSF) — a combined residual current device (RCD) and miniature circuit breaker (MCB) in a single 1+N-pole unit. It carries a B-curve 6A overcurrent trip and a 300mA residual current sensitivity, with a 4.5kA breaking capacity. The 70mm width means it occupies two standard modular DIN spaces in a distribution board.
What the ratings mean for fit
The B-curve 6A overcurrent characteristic trips between 3 and 5 times rated current — suited for resistive and lighting loads where inrush is moderate. The 300mA residual sensitivity is Type A, meaning it detects sinusoidal AC and pulsating DC fault currents, which covers most single-phase electronic loads (switched-mode supplies, LED drivers, VFDs). The 4.5kA breaking capacity (Icn) is the short-circuit withstand rating per EN 61009; it safely interrupts faults up to that level without upstream damage, provided the prospective short-circuit current at the installation point does not exceed 4.5kA.