What this MCCB does and where it fits
The Siemens SENTRON 3VA2340-6JP32-0AH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, designed for line protection in distribution panels and switchboards. Its interrupting capacity reaches 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V — so it handles high-fault service-entrance or sub-distribution duty where fault current runs high at lower voltages. The adjustable thermal-magnetic trip unit covers a 600 A to 4 000 A range for short-time or instantaneous pickup. The frame itself is a 400 A continuous frame. Power loss at full load is 96 W maximum — relevant for enclosure heat-rise calculations when packing multiple breakers in a single panel.
Thermal derating and ambient limits
The breaker holds its full 400 A rating from 40 °C up through 50 °C. At 55 °C it derates to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. If your panel sits in a hot machine room or near a furnace line, check the derating curve at your actual ambient before locking in the BOM.
Panel footprint and auxiliary configuration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard 3-pole MCCB footprint that fits most Siemens SENTRON mounting bases and busbar systems. The breaker ships with 2 auxiliary switches plus 1 trip alarm switch (HQ type) factory-installed, so you get remote status indication without ordering add-on modules separately. No undervoltage release, no ground-fault monitoring, and no auxiliary release are included — those are separate option modules if your application requires shunt trip or GF protection.