400 A MCCB with ETU560 — selectivity and SCCR headroom
The Siemens 3VA2340-5JQ32-0HA0 is a 3-pole SENTRON molded case circuit breaker rated for 400 A continuous current (Iu) at 40 °C through 50 °C, with the ETU560 electronic trip unit providing adjustable long-time, short-time, instantaneous, and ground-fault protection. At 240 V it interrupts 187 kA; at 415 V and 440 V, 121 kA — numbers that give real headroom for high-fault panels without cascading upstream breakers. The ETU560 trip unit supports communication (Communication Function Yes), so it can report status and events over the SENTRON bus — useful for a line-down scenario where you need remote trip indication without a separate auxiliary contact block. Note: the breaker ships without auxiliary contacts (Auxiliary contact version: Without), so if you need local status, plan for the 3VA9688-0BL30 integrated auxiliary trip or an external contact module. Thermal derating is linear above 50 °C: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C.
No special adapter plate needed for a Siemens 3VA2 panel. The ETU560 handles the overcurrent release logic; no separate relay needed for ground fault.