The Siemens 3VA2440-6HK32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with the same 400 A rating holding steady all the way up to 70 °C — no derating needed across the typical panel ambient range. That 400 A figure is the continuous current you can count on for the main feeder or a large motor branch circuit. Three-pole design, line-protection configuration, and an ETU340 electronic trip unit. Breaking capacity is the headline here: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. At 690 V the 9 kA rating is lower, but that's still adequate for many 690 V motor circuits. Insulation voltage rated 800 V. Max power loss 63.5 W.
Depth of 110 mm leaves room for rear-connected bus bars or cable lugs in a typical enclosure. The storage range covers cold warehouses and hot shipping containers without issue.