400 A MCCB with 242 kA interrupting capacity
The Siemens 3VA2340-6JQ32-0HC0 is a SENTRON molded case circuit breaker rated for 400 A continuous current at 40 °C, with a maximum breaking capacity of 242 kA at 240 V. That interrupting rating drops to 187 kA at 415 V and 440 V, then to 121 kA at 500 V, and 40 kA at 690 V — so the available fault current at your service voltage is the spec that decides fit, not the headline 242 kA figure. The 800 V rated insulation voltage (Ui) confirms it is built for 690 V line-to-line systems with margin. The electronic trip unit is an ETU560, which supports communication functions and ground-fault monitoring via summation current formation on the L-conductor. A shunt trip (STL) is integrated as the auxiliary release, and two HQ auxiliary switches are fitted for status feedback to a PLC or annunciator panel.
Thermal derating and ambient limits
The 400 A rating holds from 40 °C through 50 °C. Above that, derate linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. Maximum power loss is 96 W — factor that into enclosure ventilation if the panel is tightly packed.
Mechanical endurance and dimensions
Rated for 15,000 latching operations. Panel cutout dimensions: 248 mm height, 138 mm width, 110 mm depth. The 3-pole frame is line-protection version with no undervoltage release and no phase-failure detection.