The Siemens 3VA1125-5EF36-0KH0 is a SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous current (Iu) at 40 °C through 50 °C, with a thermal-magnetic TM240 overcurrent release and a 3-pole configuration. Its interrupting capacity reaches 187 kA at 240 V, 121 kA at 415 V, and 75.6 kA at 440 V — enough to handle high-fault utility feeds or transformer secondaries without cascading upstream.
The 25 A rating holds flat from 40 °C to 50 °C, then derates to 24 A at 55 °C, 23.5 A at 60 °C, 23 A at 65 °C, and 22.5 A at 70 °C. The case dimensions — 70 mm deep, 76.2 mm wide, 130 mm high — fit the standard SENTRON 3VA mounting footprint, so it swaps into existing DIN-rail or screw-mount panels without re-drilling. Front IP40 protection keeps out tools and fingers; the enclosure itself is not sealed against washdown.