The Siemens SENTRON 5SY7505-7 is a 2-pole miniature circuit breaker (1P+N) rated at 0.5 A AC with a C-curve tripping characteristic, designed for branch-circuit protection in industrial control panels. Pollution degree 3 tells you it handles conductive dust and occasional condensation, typical of factory-floor enclosures. Rated breaking capacity is 15 kA per EN 60898 and 50 kA per IEC 60947-2 — the 50 kA figure governs for industrial installations where fault current can be high; the 15 kA covers residential/commercial coordination.
Temperature derating — the real-world rating
The 0.5 A rating holds at 35 °C but drops to 0.47 A at 40 °C, 0.45 A at 45 °C, 0.44 A at 50 °C, 0.42 A at 55 °C, and 0.4 A at 60 °C. If your panel ambient runs 50 °C, you're effectively working with a 0.44 A breaker — size upstream or downstream accordingly. Ambient range is -40 °C to 75 °C, with humidity limits per: 95% RH up to 55 °C, then derating to 35% at 75 °C.
Width 36 mm, height 90 mm. Combined terminal top and bottom means you can feed either direction. Sealable, halogen-free, silicon-free. Touch protection is built in. Overvoltage category III — suitable for fixed-installation distribution boards, not just final circuits.