The Siemens SENTRON 5SV3642-6KK01 is a 4-pole residual current operated circuit breaker (RCCB), Type A, short-time delayed, rated at 25 A and 300 mA residual sensitivity on a 400 V AC supply. Type A detection means it trips on sinusoidal AC residual currents and pulsating DC residual currents up to 300 mA — the standard for circuits with single-phase rectified loads like switched-mode power supplies or variable-speed drives. The short-time delayed characteristic (0.8 kA rated conditional short-circuit current per IEC 61008-1) prevents nuisance tripping from transient leakage or inrush in circuits with downstream surge arrestors or capacitive filters.
At 72 mm wide (4 modular width units), it occupies four 18 mm slots on the rail. Depth is 70 mm, matching the standard 70 mm installation depth for SENTRON modular devices, so it sits flush in a common distribution board without protruding past the gland plate. IP20 rating applies once installed with conductors connected — the enclosure front is touch-safe, but the terminals are not protected against water ingress.
This RCCB is specified in commercial and industrial distribution boards where earth-fault protection is required on a 4-wire (3-phase + neutral) system. The Type A characteristic makes it suitable for circuits feeding IT equipment, lighting with electronic ballasts, or small VFDs — loads that generate pulsating DC fault currents a standard Type AC RCCB might not detect. The short-time delay avoids nuisance tripping on circuits with surge protection devices or long cable runs with high capacitive leakage.