Siemens SENTRON 3VA1125-4EF46-0AA0 — 25 A, 4-Pole MCCB for Line Protection
The interrupting rating of 121 kA at 240 V gives substantial fault-current headroom for high-capacity downstream networks. With a width of 101.6 mm (4 in), height of 130 mm (5.12 in), and depth of 70 mm (2.76 in), this MCCB fits standard Siemens SENTRON panel footprints. The IP40 protection on the front face suits indoor switchboard mounting where tools-only access is acceptable. The 4-pole configuration handles three-phase-plus-neutral systems common in European and Asian distribution architectures.
Interrupting Capacity — What the Ratings Mean
The interrupting capacity drops with system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. Temperature derating is mild: the 25 A rating holds steady from 40 °C through 50 °C, then drops to 24 A at 55–60 °C and 23 A at 65–70 °C. In a crowded panel with ambient above 50 °C, plan for a 1–2 A reduction per pole rather than a full frame upsizing.