The Siemens SENTRON 3VA2340-8HN32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 400 A at 40–50 °C and an ETU350 electronic trip unit. Its breaking capacity reaches 440 kA at 240 V, 330 kA at 415 V, and 52.5 kA at 690 V — meaning it can safely clear high-fault currents in low-voltage distribution without upstream cascading.
At 240 V the 440 kA rating covers most North American transformer-fed services; at 415/440 V the 330 kA figure suits heavy industrial switchboards. Thermal derating starts at 55 °C — the 400 A rating holds through 50 °C, then drops to 385 A at 55 °C, 370 A at 60 °C, and 340 A at 70 °C. Factor that into the panel ambient if the breaker sits near transformers or drives.
Max power loss is 96 W, so allow convection clearance.