Line protection breaker with high interrupting capacity
The Siemens 3VA1125-5ED12-0AA0 is a 1-pole SENTRON molded case circuit breaker (MCCB) rated for line protection. Its TM210 thermal-magnetic release provides LI protection — fixed instantaneous trip at 320 A and thermal overload curve centered on the 25 A continuous rating at 40 °C. The interrupting capacity tells the story: 121 kA at 240 V AC handles high-fault utility feeds or transformer secondaries, while the 9 kA at 415 V AC covers most European industrial distribution. That 121 kA figure means this breaker can safely clear a bolted fault on a 240 V service without upstream fuses — a real advantage in retrofit panels where available fault current is high.
DIN-rail footprint and thermal derating
At 25.4 mm wide (1 inch) and 70 mm deep, this single-pole MCCB snaps onto standard DIN rail and leaves room for adjacent breakers in a multi-pole group. The 130 mm height fits within a typical 200 mm enclosure depth with wiring clearance. Thermal derating is mild: the 25 A rating holds through 50 °C, then steps to 24 A at 55–60 °C and 23 A at 65–70 °C. For a panel running warm near a drive or transformer, that derating curve means you can still load it to 23 A without nuisance tripping.