What this MCCB delivers
The Siemens SENTRON 3VA2125-7HN46-0AA0 is a 4-pole molded case circuit breaker rated for 25 A continuous current, built around the ETU350 electronic trip unit. That trip unit gives you adjustable overload and short-circuit protection curves — useful when coordinating downstream feeders in a distribution panel or isolating a motor branch circuit. The 25 A rating holds flat across the full ambient range from -25 °C to 70 °C, so no derating headache in a warm enclosure. Breaking capacity is where this breaker earns its keep: 330 kA at 240 V AC, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V. At 240 V that's a serious SCCR rating — it can interrupt a massive fault without cascading upstream, which makes it a candidate for high-fault service entrance or main breaker duty where the available fault current is high. The 800 V rated insulation voltage (Ui) confirms it's built for 690 V line-to-line systems with margin. IP40 on the front means tools or fingers won't reach live parts in a closed panel — standard for indoor distribution boards.
Dimensions and panel fit
At 181 mm tall, 140 mm wide, and 86 mm deep, this breaker fits the standard SENTRON 3VA2 mounting footprint. The 140 mm width across four poles is the dimension to check against existing busbar spacing or phase barriers in a retrofit panel. Depth of 86 mm leaves room for rear-connected busbars or a cable duct behind the breaker.