What it is and what the ratings mean
The Siemens 5SV5646-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON family, rated 63 A with a 300 mA residual trip threshold, Type A, for 230/400 V AC 50 Hz networks. Type A detection means it responds to sinusoidal AC faults and pulsating DC faults — the standard for circuits with single-phase rectified loads like switched-mode power supplies or variable-speed drives. The 6 kA short-circuit current rating (SCCR) per IEC 61008-1 means the device can safely interrupt a fault up to that level without welding contacts or cascading damage upstream; the 0.8 kA rated conditional short-circuit current with the specified series fuse (max 80 A) covers the coordination requirement for most residential and light commercial distribution boards.
Where it goes and how it mounts
Snaps onto a DIN rail (REG) in any mounting position, occupying 4 modular width units at 60 mm grid spacing. The 70 mm installation depth matches standard distribution board enclosures — no deep-can requirement. Supply can enter from top or bottom, which simplifies panel wiring when busbars or pre-formed cable runs dictate the feed direction. IP20 with conductors connected and distribution board installed; that's the usual protection for inside a locked cabinet, not for wet or dusty environments.