The Siemens SENTRON 3VA2340-5HN42-0HC0 is a 4-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C ambient, with a maximum breaking capacity of 187 kA at 240 VAC. That 187 kA figure at 240 V tells you this breaker handles high-fault-current scenarios typical in large distribution panels or industrial switchboards — it's sized for the main incoming feed, not branch protection. The 400 A rating holds steady through 50 °C; above that it derates in 5 °C steps down to 340 A at 70 °C, which matters if you're stuffing this into a hot enclosure with other gear.
Breaking capacity across voltages
Breaking capacity drops as voltage rises: 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. That 7.5 kA at 690 V is the number to check if you're on a 690 V industrial system — it's much lower than the 240 V headline, so coordination studies need to use the right voltage column. The breaker is designed for line protection (cable and busbar protection), not motor or generator protection, per the product designation.
Integrated shunt trip and auxiliary switches
This variant ships with a shunt trip (STL) release and two HQ auxiliary switches built in. The shunt trip lets you remotely trip the breaker via a control signal — useful for emergency-stop circuits or remote shutdown sequences. The two auxiliary switches provide status feedback (open/closed) to a PLC or indicator panel. No undervoltage release, no ground-fault monitoring, no communication module on this order code; it's a straightforward line-protection breaker with remote trip capability.