What this MCCB carries — and what that means on the panel
The Siemens 3VA1112-5EF36-0KH0 is a 3-pole SENTRON molded case circuit breaker rated 125 A continuous at 40 °C, with an interrupting capacity of 187 kA at 240 V. That 187 kA figure is the SCCR — short-circuit current rating — at 240 V; it drops to 121 kA at 415 V and 75.6 kA at 440 V, so if your fault-current study lands in that range, this breaker handles it without cascading upstream. The 125 A rating holds steady through 50 °C, then derates to 122 A at 55 °C and 114 A at 70 °C — useful to know if this lands in a hot enclosure or near other heat sources. This is a line-protection design (not motor-protection or feeder), so it's built for distribution panels where the job is clearing faults on branch circuits. It ships with a shunt trip (STL) and two auxiliary switches plus one trip alarm switch HQ — that means you can remote-trip it and get status feedback without adding a separate accessory block.
Panel fit — dimensions and integration
The breaker measures 70 mm deep by 76.2 mm wide by 130 mm tall. That 76.2 mm width (3 inches) is the standard 3-pole MCCB footprint.