What this MCCB is and what it protects
The Siemens SENTRON 3VM1125-3ED22-0AA0 is a 2-pole molded case circuit breaker (MCCB) designed for line protection — meaning it sits upstream of a feeder or branch circuit, not on a motor starter. It carries a TM210 thermal-magnetic overcurrent release, so the thermal element handles overloads and the magnetic element handles short-circuits. Rated 25 A continuously at 40 °C ambient, it holds that rating up through 50 °C before a gentle derate begins: 24 A at 55–60 °C, 23 A at 65–70 °C. For a panel running warm, that 2 A drop at the top end is worth noting if you're loading the breaker near its nameplate.
Breaking capacity — where it fits in a distribution scheme
Interrupting rating is 76 kA at 240 V AC and 53 kA at 415 V AC. At 415 V, that's a healthy figure for a 25 A frame — it clears high-fault scenarios without needing a current-limiting upstream fuse in most industrial panels. The 76 kA at 240 V means it handles the full available fault current on a typical 240 V delta or split-phase service. Rated operating voltage is 415 V AC and 250 V DC; the DC figure covers battery-bank or DC-bus protection where the 2-pole series trip handles the arc.
Panel fit and integration
Dimensions: 70 mm deep, 50.8 mm wide, 130 mm tall. At roughly 2 inches wide, it occupies a single 2-pole MCCB slot in a SENTRON distribution panelboard or a 3VA/3VM mounting base. Front face carries IP40 protection — splash protection not guaranteed, but fine for a dry indoor enclosure. No trip indicator, no undervoltage release, no communication function — this is a straight thermal-magnetic breaker with no auxiliary electronics.