What this 400 A MCCB does and where it fits
The Siemens SENTRON 3VA2340-7HN32-0JL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, designed for line protection in distribution panels. Its 138 mm wide, 248 mm tall, 110 mm deep frame fits standard switchboard mounting — no special adapters needed for a retrofit into a SENTRON-based lineup. Rated uninterrupted current holds at 400 A up to 50 °C ambient, then derates linearly: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your enclosure runs hot — say a packed switchboard near a furnace line — that 340 A floor at 70 °C still covers most 300 A feeder taps without upsizing the frame.
Breaking capacity — what the numbers mean for your fault duty
This MCCB delivers 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V. Those are the maximum prospective fault currents it can safely interrupt at each voltage level. For a 480 V panel with an available fault current of 150 kA, you have nearly 40 kA of headroom above the requirement — selectivity coordination stays easier when the upstream device doesn't have to worry about the breaker failing open.
Integration notes for the panel builder
Three-pole design with a voltage-trigger capability and a trip indicator — useful for remote fault annunciation without opening the door. No undervoltage release, no ground-fault monitoring, no communication function onboard; if you need those, you're looking at a different 3VA variant or an external module. Power loss at rated current is 96 W maximum — account for that in your enclosure thermal calculation. Storage range spans -40 °C to 80 °C; operating ambient runs -25 °C to 70 °C. The 80 °C storage max is a shipping and idle-warehouse limit, not a running condition — don't mount it next to a steam line.