Siemens 3VA2440-8HK42-0AA0 — 400 A SENTRON MCCB with ETU340 release
The Siemens 3VA2440-8HK42-0AA0 is a 4-pole molded case circuit breaker (MCCB) from the SENTRON series, designed for line protection in industrial power distribution panels. It carries a continuous current rating of 400 A across the full operating temperature range from -25 °C to 70 °C, with no derating needed up to 70 °C — that means it holds its full 400 A rating even in a warm enclosure. The interrupting capacity is substantial: 440 kA at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V. For a 400 A frame, these numbers mean it can handle high-fault-current scenarios without cascading failure — typical for large transformer secondaries or motor control centers with high short-circuit capacity. The overcurrent release is an ETU340 electronic trip unit, configurable for the protection curve. The breaker measures 248 mm high, 184 mm wide, and 110 mm deep — a standard SENTRON 3VA footprint that fits existing panel cutouts for this frame size.
Integration and mounting
The 184 mm width and 110 mm depth fit standard SENTRON 3VA panel cutouts. Four poles mean it can switch three-phase plus neutral in a single unit, simplifying wiring in 4-wire distribution systems. Power loss is rated at 63.5 W maximum — account for this heat in the enclosure thermal budget, especially when grouping multiple breakers in a confined panel. The rated insulation voltage is 800 V, and the storage temperature range is -40 °C to 80 °C, which covers most warehouse and shipping conditions.