The Siemens 5SP3863-2 is a SENTRON main miniature circuit breaker rated 63 A at 400 V AC, 50 Hz, with a 25 kA breaking capacity certified per EN 60898. Three-pole construction, busbar-mounted, occupying 4.5 modular width units on a 40 mm busbar system per DIN 43870 Part 2.
For a main breaker in a residential or light commercial panel, 25 kA covers most utility transformer fault levels. The insulation voltage (Ui) is rated 690 V, and overvoltage category IV means it is suitable for the service entrance.
Fastens directly onto a 40 mm busbar system per DIN 43870 Part 2 — no DIN rail adapter needed. Infeed at the box terminal; the design assumes power supply from the lower section of the meter panel. Sealable via locking slide with lock, wire seal, cable ties, or Antilux. Depth is 89.5 mm; enclosure depth is 76.3 mm.
Thermal derating and ambient range
Rated 63 A at 30 °C ambient. Derates to 59.85 A at 40 °C, 58.275 A at 45 °C, 56.7 A at 50 °C, and 55.125 A at 55 °C. Shock resistance: 30 g, at least 3 impacts, 11 ms duration. Surge voltage resistance rated 6 kV.