400 A MCCB with shunt trip — what the ratings mean for your panel
The Siemens 3VA2340-6HL32-0JA0 is a 3-pole SENTRON molded case circuit breaker rated for 400 A continuous current across 40 °C to 50 °C ambient. Above 50 °C it derates linearly — 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, 340 A at 70 °C. That derating curve is the one you size against if the breaker lives in a warm enclosure or next to other heat sources. Breaking capacity hits 242 kA at 240 V and stays at 187 kA through 415–440 V, then drops to 121 kA at 500 V and 7.5 kA at 690 V. The 242 kA figure at 240 V is what you need for high-fault utility or transformer-secondaries; the 690 V rating is low enough that you verify coordination if the breaker sees a 690 V bus. This variant ships with a shunt trip release (STL) as the auxiliary release. No undervoltage release, no ground-fault monitoring, no auxiliary switch — the shunt trip is the only add-on fitted from the factory. If you need UVR or GF protection, you are ordering a different suffix or adding modules in the field.
Mounting and integration — dimensions and panel fit
The breaker measures 248 mm high × 138 mm wide × 110 mm deep. That 138 mm width is the standard 3-pole SENTRON 3VA2 footprint — it fits the same mounting base and busbar system as the rest of the 3VA2 family. Panel cutout and drilling pattern match the 3VA2 line; no adapter plate needed if you are swapping within the series.
Selectivity and coordination — Icw and Ii settings
Rated short-time withstand current (Icw) is 4 000 A; instantaneous pickup (Ii) is 600 A. That 600 A magnetic threshold means the breaker holds through motor inrush up to about 1.5× rated current before the instantaneous element clears a hard fault. For selectivity studies, the Icw of 4 kA tells you the downstream devices must clear before the 3VA2340-6HL32-0JA0 sees that level through its short-delay band.