Rated for the meter panel — 63 A, E-curve, 25 kA
The Siemens 5SP3763-2 is a 1-pole SENTRON main miniature circuit breaker rated 63 A at 230 V AC, 50 Hz, with an E tripping characteristic and a 25 kA breaking capacity certified per EN 60898. The E-curve is the key selection callout here: it trips magnetically between 10× and 20× In, so it holds through the inrush of larger transformers or long cable runs where a B- or C-curve would nuisance-trip. For a main breaker feeding a distribution board, that delayed magnetic release is exactly what keeps the service entrance from dropping on a downstream transformer energization.
Busbar mount, 1.5 width units — panel fit
Mounts directly on a 40-mm busbar system per DIN 43870 Part 2, which is the standard grid for European meter-panel layouts. The 1.5 width-unit footprint (roughly 27 mm) and 89.5 mm depth let it slot into the same cutouts as other SENTRON 5SP3 devices — no re-spacing needed if you're swapping into an existing panel. The spring-loaded outgoing terminal is tool-less for the load side; the infeed uses a box terminal for the line side.
Mechanical endurance is 20 000 switching cycles typical. Shock-rated to 30 g (3 impacts, 11 ms duration) and vibration-rated to 2 g per IEC 60068-2-6 (20 frequency cycles, 5 to 150 Hz).