What it is and what it does
The Siemens SENTRON 5SV3656-6 is a 4-pole residual current circuit breaker (RCCB), type A, rated 63 A with a 300 mA trip threshold. It operates on 500 V AC at 50 Hz and carries a 10 kA short-circuit current rating (SCCR). Type A detection means it picks up both sinusoidal AC residual currents and pulsed DC residual currents up to 6 mA — the kind you get from single-phase rectifiers in VFDs, switching power supplies, and LED drivers. That 300 mA sensitivity is a common choice for general distribution where you want earth-fault protection without nuisance tripping from normal leakage on long cable runs or filtered loads. The 10 kA SCCR at 500 V tells you this RCCB can safely interrupt a fault up to that level without welding its contacts or cascading upstream — critical for selectivity coordination in a panel.
Where it goes in the panel
Snaps onto a DIN rail (REG profile) and takes 4 modular width units at 60 mm grid spacing. Dimensions are 72 mm wide × 90 mm high × 70 mm deep. That 70 mm installation depth is shallow enough for most standard enclosures — no deep-can required. Mounts in any orientation. Feed from top or bottom; the design is instantaneous (no intentional short-time delay), so it responds to a fault within one mains cycle. Silicon-free construction, which matters if this goes into a paint shop or coating line where silicone outgassing can cause adhesion failures. IP20 with conductors connected — fine inside a distribution board, not for wet or washdown locations.
What the ratings mean for your BOM
The 63 A rating is the continuous current the RCCB can carry without overheating. Per-pole power loss is 3.9 W at rated current in hot operating state — four poles means roughly 15.6 W total heat to dissipate inside the enclosure. If you're packing multiple devices in a small panel, that heat adds up; check your thermal budget. The 0.8 kA rated conditional short-circuit current per IEC 61008-1 is the maximum prospective fault current the RCCB can withstand when backed by a suitable overcurrent protective device (the series fuse must not exceed 63 A). The ambient temperature range is -25 °C to +45 °C operating, -40 °C to +75 °C storage. Overvoltage category III means it's rated for fixed installation downstream of the main distribution board — not for use directly at the service entrance (that's cat IV).