What this MCCB carries and where it fits
The Siemens SENTRON 3VA2340-6HN32-0JA0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C through 50 °C without derating — at 55 °C it still holds 385 A, and at 70 °C it carries 340 A. That thermal curve means this breaker is sized for a 400 A bus or feeder in a panel that sees elevated ambient temps; you don't lose headroom until past 50 °C. Breaking capacity is 242 kA at 240 V AC, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. That 242 kA figure at 240 V covers high-fault utility feeds in North American panels; the 187 kA at 415 V handles European 400 V distribution. The 40 kA at 690 V is still substantial for industrial 690 V networks. This is a line protection version — not a motor protection breaker. It's designed for cable and busbar protection in main or sub-distribution boards. The ETU350 electronic trip unit provides adjustable overload and short-circuit protection curves.
Panel fit and integration notes
Dimensions are 248 mm height, 138 mm width, 110 mm depth. The 110 mm depth is the critical dimension for shallow gland-plate enclosures — verify your back-panel clearance before committing. The 138 mm width means it occupies a standard 3-pole MCCB footprint on a DIN rail or bolted bus. Maximum power loss is 96 W at rated current. That's the heat you need to vent in the enclosure — factor it into your thermal budget, especially in a sealed cabinet with multiple breakers ganged together. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage minimum matters if this breaker sits in an unheated warehouse before installation — it's fine down to -40 °C, but don't energize it below -25 °C.
What's not on this variant
This order code comes without auxiliary contacts, without an undervoltage release, without ground fault monitoring, without phase failure detection, and without communication functions. The only auxiliary release is the shunt trip (STL). No trip indicator is fitted. If you need any of those options, you're looking at a different suffix in the 3VA2 family. Latching endurance is rated at 15,000 cycles — that's the mechanical life for the switching mechanism. For a main breaker that cycles infrequently (a few times a year), this is more than adequate. For a frequently switched load-break application, you'd want to check the electrical endurance curve separately.