The Siemens 5SY7515-8 is a SENTRON miniature circuit breaker, 2-pole (1P+N), with a D tripping characteristic rated at 1.6 A at 35 °C. The D-curve means it's designed to handle the high inrush currents from motor starters, transformers, or welding gear without nuisance tripping on startup, while still clearing faults fast.
Ratings that matter for real panels
The 1.6 A rating at 35 °C is the headline number, but this breaker is thermally derated across the board: 1.52 A at 40 °C, 1.48 A at 45 °C, 1.44 A at 50 °C, 1.4 A at 55 °C, and 1.36 A at 60 °C. If your panel runs warm — and most industrial enclosures do — size the load against the derated figure at your ambient, not the 35 °C sticker. The D-curve trips between 10x and 20x In, so for a 1.6 A breaker, magnetic trip happens between 16 A and 32 A. That's the window that keeps it from dropping out on motor inrush but still catches a bolted fault.
The 5SY7515-8 takes 2 modular width units (36 mm wide) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. The quick assembly system and any mounting position mean it slots into a populated rail without rework.