The 5SP3725-2 is a Siemens SENTRON 1-pole miniature circuit breaker (MCB) rated 25 A with a characteristic E trip curve and a 25 kA breaking capacity at 230 V AC. The E characteristic is designed for selective coordination — it tolerates short-duration inrush without tripping, so a downstream fault clears before this breaker opens, keeping the rest of the feeder live. That makes it a main or upstream breaker in a distribution board, not a final-circuit device protecting a single load. Overvoltage category IV and 6 kV surge voltage resistance confirm it is rated for the service entrance or main panel, not just sub-distribution. Temperature derating is built in: at 40 °C ambient the continuous current rating drops to 23.75 A; at 50 °C it is 22.5 A.
Occupies 1.5 modular width units on the DIN rail. Depth is 89.5 mm, with an enclosure depth of 76.3 mm. Height is 151.3 mm. Fastens via busbar connection. Infeed at the box terminal is supported; outgoing feeder uses a spring-loaded terminal. Protection class IP40 with connected conductors — suitable for dry indoor enclosures, not washdown or outdoor exposure. Sealable design allows locking the cover to prevent unauthorized operation.
Designed and tested to EN 60898 for breaking capacity and IEC 81346-2 / DIN EN 61346-2 for function designation (F). Insulation voltage rated 690 V. Shock resistance tested at 30 g, 3 impacts, 11 ms duration.