The Siemens SENTRON 3VA2340-5HN42-0KA0 is a 4-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with the ETU350 electronic overcurrent release handling the protection curve. The 187 kA interrupting capacity at 240 V drops to 121 kA at 415 V and 440 V, then to 75.6 kA at 500 V, and 17 kA at 690 V — these are the fault currents it can safely clear without rupturing, so the voltage at the fault point governs which SCCR tier applies. Current derating matters for warm panel environments: the breaker holds 400 A up to 50 °C, then steps down to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. This is a line-protection variant, meaning it is configured for feeder and main protection rather than motor or generator protection. It ships without auxiliary contacts, without a trip indicator, without undervoltage release, without ground-fault monitoring, and without communication — it is a pure power path with the shunt trip (STL) as the only auxiliary release. The integrated auxiliary trip is order code 3VA9688-0BL33.
The breaker measures 248 mm high, 184 mm wide, and 110 mm deep. The 4-pole format with the ETU350 and shunt trip occupies the same cutout as the standard 3VA frame — verify the depth clearance for the shunt trip wiring, especially in shallow enclosures. Maximum power loss is 96 W at full rated current — factor that into enclosure thermal rise calculations. The 15,000 latching endurance cycles cover the mechanical life for frequent switching applications.