400 A MCCB with 330 kA interrupting — selectivity headroom for high-fault panels
The Siemens SENTRON 3VA2340-7HN32-0HL0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C, with a maximum interrupting capacity of 330 kA at 240 VAC. That 330 kA figure at 240 V means this breaker can safely clear a fault up to that level without upstream devices needing to intervene — critical for main or tie breakers in high-capacity switchboards where available fault current exceeds 200 kA. At 415 V the rating holds at 242 kA, and at 690 V it derates to 7.5 kA, so the application voltage dictates the fault-clearing capability you can rely on. This is a line-protection design — meaning the thermal-magnetic or electronic trip curve is set for feeder and main protection, not motor or generator protection. The continuous current rating holds flat at 400 A from 40 °C through 50 °C (–), then begins a linear derating: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C (–). If the panel ambient runs above 50 °C, the actual ampacity you can count on is the derated value, not the nameplate 400 A.
Auxiliary and release configuration — shunt trip plus four switch contacts
This variant ships with a shunt trip release (STL) for remote tripping, plus a full complement of auxiliary and alarm switches: 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ). That gives four independent signal contacts — enough to report breaker position, trip status, and a separate electrical alarm back to a PLC or BMS without adding external relays. The base switch is order code 3VA2340-7HN32-0AA0; the -0HL0 suffix adds the shunt trip and the HQ alarm switch package.
Panel integration — dimensions and mounting footprint
The breaker measures 248 mm high by 138 mm wide by 110 mm deep — 9.76 by 5.43 by 4.33 inches. That 138 mm width is the standard 3-pole MCCB footprint for this class; it fits Siemens 3VA mounting bases and panel cutouts without adapter plates. Maximum power loss is 96 W, so account for that heat in the enclosure's thermal calculation — at 400 A continuous, the breaker dissipates nearly 100 W into the panel air.