What this MCCB delivers for your feeder protection
The Siemens SENTRON 3VA2340-6KP32-0JA0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, sized for main feeder or large sub-feed protection in commercial and industrial distribution panels. Its breaking capacity reaches 242 kA at 240 VAC and 187 kA at 415/440 VAC, dropping to 121 kA at 500 VAC and 7.5 kA at 690 VAC — the 690 V figure tells you this is a 240–500 V workhorse, not a 690 V main. The 400 A rating holds flat through 50 °C, then derates to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C; if your panel ambient runs above 50 °C, size up one frame. This is a line-protection design (not a motor-protective breaker), so it coordinates with downstream branch breakers for selective tripping. The shunt trip release (STL) allows remote opening via a control signal, and the communication function supports integration with a BMS or SCADA system for status monitoring and load shedding. No undervoltage release or ground-fault monitoring is fitted on this variant.
Thermal management and panel fit
At full 400 A load the breaker dissipates up to 96 W. That heat must be vented — don't bury this in a sealed, uncooled enclosure without accounting for the temperature rise. The 110 mm depth, 138 mm width, and 248 mm height fit standard MCCB mounting footprints; verify the busbar or cable lug clearance on your existing panel layout before committing the BOM line.