SENTRON 3VA2125-0KQ46-0AA0 — MCCB with ETU860 electronic trip unit
It carries a continuous current rating of 25 A and a breaking capacity of 440 kA at 415 V AC — that figure tells you it can safely interrupt fault currents up to that level without cascading upstream, critical for high-fault installations like transformer secondaries or large motor control centers.
The 4-pole design with the ETU860 electronic trip unit gives you adjustable N-conductor protection from OFF to 40%–160% of the rated current — useful for systems where neutral loading varies. The 800 V rated insulation voltage means it's comfortable on 690 V line-to-line systems, and the 187 kA breaking capacity at 690 V confirms it holds up at higher voltage levels too. Continuous current holds at 25 A across the full ambient range from 40 °C to 70 °C — no derating curve to chase. That's unusual for an MCCB this size and simplifies panel thermal calculations. The minimum adjustable trip setting is 38 A, with a maximum of 300 A, so the breaker can be tuned to protect a specific load rather than just the bus.
The breaker measures 140 mm wide, 181 mm tall, and 86 mm deep — a standard 4-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without special adapters. The ETU860 trip unit is programmable via the front interface, so you can set the long-time, short-time, instantaneous, and ground-fault parameters during commissioning without opening the cover.