The Siemens SENTRON 3VA2340-6JQ32-0JC0 is a 3-pole molded case circuit breaker rated for 400 A continuous current with a 242 kA interrupting capacity at 240 V. That breaking capacity drops to 187 kA at 415 V and 440 V, and 121 kA at 500 V, so it handles high-fault utility feeds and transformer secondaries without cascading upstream. The ETU560 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves — line protection version, not motor protection.
Ratings and thermal derating
Full 400 A rating holds from 40 °C through 50 °C ambient; above that it derates linearly to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. That means in a warm enclosure — say a switchboard near a furnace line — you lose 25 % of the headroom at 70 °C. Plan the gland-plate fill factor accordingly; the 138 mm width and 248 mm height fit a standard MCCB slot, but the 110 mm depth leaves room for rear-access bus bars.
Communication and auxiliary hardware
This variant ships with a built-in communication function and two HQ auxiliary switches. The integrated shunt trip (STL) is pre-installed.