The Siemens 5SL6463-6 is a SENTRON miniature circuit breaker — 4-pole, B-curve, rated 63 A at 400 V AC with a 6 kA breaking capacity per EN 60898 (also 6 kA per IEC 60947-2). Four poles (4P) switch all lines simultaneously, making it a full-disconnect device for three-phase plus neutral circuits.
The 5SL6463-6 occupies 4 modular width units (72 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. Halogen-free and silicon-free construction matters in clean-room or high-reliability environments where outgassing can contaminate contacts or optics.
What the B-curve and breaking capacity mean in practice
The B-curve (tripping characteristic class B) is the most sensitive of the common curves — it trips magnetically at 3–5× In, so a 63 A breaker will hold 189 A to 315 A for a few milliseconds before instant-trip. That makes it suitable for circuits with low inrush: resistive loads, small control transformers, lighting banks. For motor circuits or high-inrush loads, a C- or D-curve would be more appropriate. The 6 kA breaking capacity (EN 60898) and 6 kA (IEC 60947-2) are identical here — this breaker is rated for residential and light-commercial infrastructure (per its suitability listing). The 400 V AC rated voltage (440 V max multi-phase) covers standard three-phase distribution in most regions.