What this MCCB delivers on the line
The Siemens 3VA1125-6EF46-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — meaning it sits upstream of branch feeders, guarding against overloads and short circuits in a distribution panel. Four poles handle three-phase plus neutral, or a second parallel path in DC networks per the 3VA device manual. Rated 25 A continuous at 40 °C ambient, it carries that current without derating up to 50 °C; at 55 °C it still holds 24 A, and at 70 °C it delivers 23 A — so a warm enclosure doesn't force a costly upsizing. Breaking capacity is the headline: 220 kA at 240 V AC, 154 kA at 415 V, and 121 kA at 440 V. Those numbers mean it clears high-fault currents without rupturing — critical for panels fed by large transformers or close to the utility service entrance. At 500 V and 690 V the rating drops to 17 kA, still adequate for most motor-control center applications.
Panel fit and mounting
Dimensions are 101.6 mm wide by 130 mm tall by 70 mm deep — a 4-inch wide footprint that fits standard Siemens SENTRON mounting plates and busbar systems. The front face carries an IP40 protection rating, meaning tools and fingers stay out, but the body is not sealed against washdown. Mount it in a dry indoor panel; no gland-plate or gasket concerns. The TM240 overcurrent release is a thermal-magnetic type — thermal element handles overloads, magnetic coil handles short-circuit trips. No undervoltage release, no shunt trip, no communication module on this variant. It's a straight protection device: wire it in, set the load, and it trips when it needs to.