The Siemens SENTRON 3VA2340-5HN32-0CL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current and a breaking capacity of 187 kA at 240 V AC — that's the peak short-circuit current it can safely interrupt without welding or exploding, sized for high-fault utility feeds or transformer secondaries. It's a line-protection design (no ground-fault module, no communication card), fitted with an undervoltage release and a full auxiliary switch set: 2 auxiliary switches plus a trip alarm and an electrical alarm switch. The 400 A rating holds flat from 40 °C up to 50 °C, then derates to 340 A at 70 °C — useful to know if the breaker sits in a hot enclosure near other heat sources.
What the breaking capacity means for your panel
At 415 V and 440 V it still handles 121 kA; at 500 V it drops to 75.6 kA, and at 690 V it's 7.5 kA. The 400 A continuous rating is the same across 40–50 °C ambient; above that, derate per the table to 340 A at 70 °C.
Physical fit & integration
The undervoltage release (UVR) is built in, so if your safety circuit drops power the breaker trips automatically. The auxiliary switch configuration (2 aux + trip alarm + electrical alarm) gives you status feedback for a PLC or annunciator without adding external relays.