What the breaking capacities mean for your panel
The 3VA2125-6HM46-0FJ0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in distribution panels. Its headline figure is the breaking capacity: 242 kA at 240 V AC and 187 kA at 415 V AC — that means it safely interrupts fault currents up to those levels without welding contacts or cascading upstream. At 690 V the capacity drops to 3.75 kA, which still covers most industrial motor feeders on a 690 V bus. The 4-pole (3 phases + neutral) construction suits TN or TT systems where neutral protection is required. Rated continuous current Iu is 25 A, and the breaker holds that rating up to 50 °C ambient. Above 50 °C it derates linearly: 24.0625 A at 55 °C, 23.125 A at 60 °C, 22.1875 A at 65 °C, and 21.25 A at 70 °C. If your panel internal temperature exceeds 50 °C, size the load accordingly — the thermal curve is already in the spec. The overcurrent release is an ETU330 electronic trip unit (adjustable LSI curves). Auxiliary contacts are built in: 2 auxiliary switches plus 1 trip alarm switch (HP version). The breaker also integrates an undervoltage release with leading NO contacts, part number 3VA9908-0BC24, and a ground-fault monitoring function using summation current on L+N. No communication module or phase-failure detection is fitted on this variant — it's a pure protection device, not a smart breaker.
Panel fit and mounting
Dimensions: 107 mm deep, 140 mm wide, 181 mm high. The 140 mm width is standard for a 4-pole MCCB in the 3VA2 frame — it occupies the same footprint as the basic switch 3VA2125-6HM46-0AA0. Front protection is IP40; the enclosure should be rated for the environment. Latching endurance is rated at 20 000 operations. Storage temperature range is -40 °C to 80 °C; operating range is -25 °C to 70 °C. Maximum power loss is 1 W.