What this MCCB is and what the ratings mean
The Siemens 3VA1125-4ED46-0AA0 is a SENTRON molded case circuit breaker (MCCB) for line protection, rated 25 A continuous at 40 °C and carrying a 4-pole configuration. That 25 A holds steady through 50 °C — only drops to 24 A at 55 °C and 23 A at 70 °C, so it handles warm panel environments without derating drama. The interrupting rating is the headline: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and still 11.9 kA at 690 V. That means it can safely clear a fault upstream of a large transformer or a high-capacity bus without needing a current-limiting fuse ahead of it.
Overcurrent release and protection design
The overcurrent release is a TM210 — a thermal-magnetic trip unit. Thermal element handles overloads (slow response to sustained overcurrent), magnetic element handles short-circuits (instantaneous on high fault current). No undervoltage release, no ground-fault monitoring, no communication function on this variant. It's a straight line-protection MCCB: bolted in, wired through, trips when it needs to. Power loss is 8.5 W max, which is modest for a 4-pole 25 A frame.
Physical fit and environment
Dimensions: 70 mm deep, 101.6 mm wide, 130 mm tall. That's a standard MCCB footprint — fits most panel-mounted or DIN-rail adapter bases in the SENTRON family. Front face is IP40, so it's protected against tools and wires >1 mm but not sealed against moisture. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The IP40 front means it belongs in a clean indoor panel, not a washdown zone.