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 800 V rated insulation voltage (Ui) keeps it comfortable on 480 V and 600 V class systems. 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. If the panel ambient runs hot, size the load accordingly — the full 400 A is only available up to 50 °C.
Integration and mounting
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is standard for a 3-pole 400 A frame — drops into a typical MCC bucket or panel cutout sized for a 400 A SENTRON breaker. No special adapter plate needed for a Siemens 3VA2 panel. The shunt trip (STL) is built in (Design of the auxiliary release: Shunt trip (STL)), and the ground-fault monitoring uses summation current formation on the L-conductor. The ETU560 handles the overcurrent release logic; no separate relay needed for ground fault.