What this MCCB delivers — and what the ratings mean for your panel
The Siemens 3VA2340-6HN32-0JH0 is a SENTRON molded case circuit breaker rated for 400 A continuous at 40 °C, 3-pole, designed for line protection in distribution panels. The 242 kA breaking capacity at 240 V AC means it can safely interrupt very high fault currents without upstream cascading — useful for main or feeder positions near large transformers. At 415 V the rating holds at 187 kA, and at 690 V it drops to 7.5 kA, so the voltage class of your system decides the available fault current this breaker can clear. The continuous current is flat from 40 °C to 50 °C at 400 A, then derates to 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 MCC lineup — you need to factor that thermal curve into the load schedule. This variant includes a shunt trip release (STL) for remote tripping, plus two auxiliary switches and one trip alarm switch (HQ configuration). The shunt trip lets a safety PLC or E-stop circuit open the breaker remotely, which is standard for emergency-off chains. No undervoltage release is fitted, so it will not drop out on a sag — that is by design for line protection where you want the breaker to stay closed unless commanded or overcurrent-tripped.
Physical fit and panel integration
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. This 3-pole MCCB mounts on DIN rail or backplate. Depth of 110 mm (4.33 in) fits most enclosures. Maximum power loss is 96 W at rated current. That heat has to be vented or conducted out of the enclosure — factor it into your thermal budget, especially in a multi-breaker lineup.
Compliance and documentation
As a SENTRON MCCB, this breaker carries the usual Siemens compliance package: IEC 60947-2 for low-voltage switchgear, UL 489 listing for the North American market, and CE marking for European installations. RoHS and REACH declarations are standard from Siemens. The order code includes the -0JH0 suffix which encodes the factory-fitted accessories (shunt trip, auxiliary switches, trip alarm).