The Siemens 5SP3763-2XX03 is a SENTRON-series main miniature circuit breaker (MCB) — one pole, 63 A rated current, E tripping characteristic, designed as the main disconnect in residential and infrastructure meter panels. The E-curve (typically 10–20× In magnetic trip) suits it for transformer or long-cable protection where inrush is higher than a standard B or C curve would tolerate without nuisance trips.
Mounts on a 40-mm busbar system per DIN 43870 Part 2 — the standard meter-panel rail in European residential and light-commercial builds. The 1.5 width units (roughly 27 mm on a DIN rail) and 76.3 mm enclosure depth fit the compact meter-cabinet footprint. Infeed is at the box terminal; outgoing feeder uses spring-loaded terminals, so no screw torqueing on the load side. The switch position indicator shows OFF = green, ON = red — a quick visual for commissioning or troubleshooting. Ambient range -25 to +55 °C covers unheated utility rooms and outdoor cabinets in moderate climates.
Wire range and termination
Solid and stranded conductors 2.5 to 50 mm² — that is a wide lugging range, from a 14 AWG control wire up to a 1/0 AWG feeder. The spring-loaded outgoing terminal handles the same range on the load side. Sealable (tamper-evident cover) for utility-metering applications where the supply authority needs to lock the main breaker.