The Siemens 5SL3208-7MB is a SENTRON 5SL3 miniature circuit breaker, 2-pole, C-curve, rated 8 A at 400 V AC. The 2-pole form factor (2 width units, 36 mm wide) breaks both phase and neutral on a single-phase 230 V supply, or two phases on a 400 V three-phase system. Note it does not switch the neutral independently (neutral conductor switching: No).
Termination and environment
Terminals accept solid or stranded conductors from 0.75 mm² up to 25 mm², with a tightening torque of 2.5 to 3 N·m. That range covers common building wire sizes from 1.5 mm² lighting circuits up to 6 mm² or 10 mm² feeder tails — no adapter lugs needed for standard panel wiring. That covers unconditioned electrical rooms and outdoor enclosures in most climates, though the 45 °C upper limit means derating applies if the breaker is packed tightly in a high-ambient panel. IP20 protection (with connected conductors) is standard for finger-safe installation inside a closed distribution board — not for wet or dusty locations without an outer enclosure.