What it is and what the ratings mean
The Siemens 5SY7310-7CC is a SENTRON miniature circuit breaker (MCB) with a 10 A rated current at 35 °C ambient, C tripping characteristic, and 3-pole construction. The C-curve means it trips between 5 and 10 times rated current — standard for motor circuits and moderate inrush loads where you need to ride through starting current without nuisance tripping. The 25 kA breaking capacity per IEC 60947-2 tells you it can safely interrupt a fault current up to that level at 440 V AC multi-phase, which is the typical short-circuit rating for industrial panel feeders. Pollution degree 3 and overvoltage category III confirm it's rated for the industrial environment, not just residential.
Temperature derating — the real usable current
The 10 A rating holds at 35 °C. At 40 °C it derates to 9.27 A; at 45 °C to 8.88 A; at 50 °C to 8.47 A; at 55 °C to 8.04 A. If your panel ambient runs above 35 °C, the actual continuous current you can pass is lower — size the load accordingly. The operating range spans -40 °C to 75 °C, so it handles cold starts and hot enclosures within those limits.
Mounting and panel fit
Snaps onto DIN rail via the quick assembly system; any mounting position is permitted. The housing is 3 modular width units (54 mm wide) with a depth of 76 mm and installation depth of 70 mm. Combined terminals at top and bottom accept wiring without needing separate accessories. IP20 with connected conductors — suitable for enclosed panel use, not washdown areas.