The Siemens 3VA2340-5JQ42-0CL0 is a 4-pole SENTRON molded case circuit breaker rated for 400 A continuous at 40 °C — line protection version with an ETU560 electronic trip unit. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, and still holds 17 kA at 690 V, so it handles high-fault utility feeds or transformer secondaries without cascading upstream. The 184 mm width and 248 mm height fit standard SENTRON panel cutouts; depth is 110 mm.
At 55 °C it drops to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A.
Integration notes
Ground-fault monitoring uses summation-current formation on L + N — it measures the vector sum of phase and neutral currents to detect leakage. No phase-failure detection built in; if you need that, it's handled by the ETU or an external relay. Latching endurance is 15,000 operations, which is typical for a distribution breaker not cycled daily.