What this MCCB delivers for the panel
The Siemens 3VA1125-3EF32-0HC0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels. It carries a 25 A continuous rating at 40 °C, holds that rating through 50 °C, then derates slightly to 23 A at 70 °C — so in a warm enclosure you lose only about 8 % of headroom. The 3-pole design with a shunt trip release (STL) means it can be remotely tripped, which is handy for emergency-off circuits or interlocked disconnects.
Breaking capacity — what the numbers mean for coordination
This MCCB delivers 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — those are the interrupting ratings you need for selective coordination studies. At 500 V and 690 V it still breaks 11.9 kA, so it handles most industrial low-voltage fault levels without cascading upstream. The rated insulation voltage is 800 V, which covers 480/277 V and 600 V systems with margin.
Panel fit and wiring notes
The MCCB measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that mounts on a DIN rail or panel-mount adapter. The shunt trip release occupies one auxiliary slot; the design also accommodates two auxiliary switches (HQ type). Max power loss is 8.5 W, so ventilation in a sealed enclosure is not critical but should be accounted for in thermal calculations.