What the ratings mean for fit
The Siemens SENTRON 3VA2340-6KP32-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with a thermal derating curve that drops to 300 A at 70 °C — meaning in a warm enclosure you size it for the ambient, not the nameplate. Breaking capacity runs from 242 kA at 240 V down to 7.5 kA at 690 V; at 415 V it still interrupts 187 kA, which covers most industrial distribution panels without an upstream current-limiting fuse. The breaker carries a shunt trip release (STL) as the auxiliary release, with no undervoltage release or ground-fault monitoring module fitted on this variant. Communication function and other measurement function are present — the base switch is order code 3VA2340-6KP32-0AA0, and this -0HA0 suffix adds the trip-indicating electronics.
Panel integration and mounting
Footprint is 138 mm wide by 248 mm tall by 110 mm deep — a standard MCCB cutout for a 3-pole frame at this current level. Bolts onto the mounting plate; no DIN-rail clip on this size. At 96 W maximum power loss, allow ventilation or spacing in the enclosure to keep the internal ambient below the 70 °C operating maximum. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The 400 A rating holds through 50 °C, then derates linearly — at 55 °C it's 375 A, at 60 °C it's 350 A, at 65 °C it's 325 A, at 70 °C it's 300 A. If your panel ambient sits at 55 °C, the breaker is good for a 375 A load, not 400 A.