What this RCCB covers
The Siemens SENTRON 5SV5347-0MB is a 4-pole residual current circuit breaker (RCCB), Type AC, rated 80 A with 30 mA trip sensitivity at 400 V AC. It is designed for instantaneous fault clearing — no intentional delay — so it responds to sinusoidal AC residual currents as they appear. IP20 protection applies once the distribution board is installed with conductors connected — meaning the front face is touch-safe but the terminals rely on the enclosure for ingress protection.
The 30 mA residual sensitivity is the standard threshold for personnel protection (shock hazard) per IEC 60364. Type AC detection means the device trips on sinusoidal AC residual currents only — it will not reliably detect pulsed DC or smooth DC faults. If the downstream load includes variable-speed drives, UPS systems, or rectifiers that can generate DC fault components, a Type A or Type B RCCB would be the correct choice. For purely resistive or inductive AC loads (heaters, contactor coils, incandescent lighting, motor circuits with no electronic drive), Type AC is adequate and the more economical option. The 80 A rated current at 400 V AC (3-phase + neutral) covers large submain or feeder circuits — think a panel feeding multiple smaller sub-distribution boards or a high-power HVAC unit. Power dissipation per pole at rated current is 4.1 W in the hot operating state; factor that into the enclosure thermal budget, especially when grouping multiple RCCBs in a single board.
DIN-rail snap-on mounting with any orientation permitted. The 4 MW width (72 mm) matches the standard 60 mm grid spacing. Silicon-free construction is specified, which matters for applications where silicone outgassing can contaminate sensitive contacts or optical surfaces.