What this breaker is and where it fits
The Siemens 3VA2340-6HN32-0HH0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous at 40 °C, with a 3-pole configuration designed for line protection in commercial and industrial distribution panels. Its interrupting capacity reaches 242 kA at 240 VAC and 187 kA at 415 VAC, so it handles high-fault-current scenarios like utility transformer secondaries or large motor control centers without cascading failure upstream. The breaker ships with a shunt trip (STL) release and a complement of 2 auxiliary switches plus 1 trip alarm switch (HQ), which means it can be wired into a remote trip circuit and provide status feedback to a PLC or annunciator panel without adding external accessories.
Thermal derating and real-world current capacity
While the breaker is rated 400 A at 40 °C, that figure holds through 50 °C — useful for enclosures with marginal ventilation. Above 55 °C the continuous current must be reduced: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your panel ambient runs above 50 °C, size the breaker for the derated value, not the nameplate.
Breaking capacity by voltage — selectivity planning
The 3VA2340-6HN32-0HH0 delivers 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. The steep drop at 690 V means this is primarily a 480 V-class breaker; for 600 V-class systems verify the available fault current stays under 7.5 kA or step to a higher-rated frame.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, and 110 mm deep. The 138 mm width is the standard 3-pole MCCB footprint for this frame size; verify the mounting pattern matches your existing bus or backplate before ordering.