400 A MCCB with 242 kA interrupting capacity — what that means for your panel
This SENTRON 3VA2340-6JQ32-0HL0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C ambient, with a maximum interrupting capacity of 242 kA at 240 V AC. That 242 kA figure means it can safely clear a fault current up to that level without the arc flashing over or the case rupturing — critical for high-fault installations like transformer secondaries or large motor control centers where available fault current is well above typical 65 kA or 100 kA breakers. At 415/440 V the rating drops to 187 kA, and at 690 V it holds at 7.5 kA, which still covers most industrial distribution panels. The thermal-magnetic trip unit is adjustable from 80 A to 400 A full scale, so you can dial it down to match a downstream load without swapping the breaker body. A trip indicator and voltage-trigger function are built in, and the auxiliary switch block includes two auxiliary switches plus a trip alarm and an electrical alarm switch — enough to signal status back to a PLC or annunciator panel.
Thermal derating and panel integration
The breaker holds its full 400 A rating up to 50 °C ambient. Above that it derates linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your panel runs hot near the top of a sealed enclosure, factor that in — at 60 °C you lose 50 A of headroom. The 138 mm width, 248 mm height, and 110 mm depth fit standard SENTRON 3VA mounting footprints; it bolts directly onto the backplate or into a fixed draw-out cradle without adapters.