What this MCCB carries
The Siemens SENTRON 3VA2340-5JQ32-0DL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with an ETU560 electronic trip unit for line protection duty. It clears up to 187 kA at 240 V and 121 kA at 415 V, so it handles high-fault utility feeds or transformer secondaries without cascading upstream. The ETU560 release provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves. The 800 V rated insulation voltage (Ui) suits 690 V systems.
Thermal derating and panel fit
Full 400 A rating holds through 50 °C ambient; above that it steps down: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your panel ambient runs over 50 °C, size the upstream conductor and bus for the derated figure, not the nameplate 400 A. Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard SENTRON 3VA2 frame footprint. The 98.5 W maximum power loss at rated load means the enclosure needs ventilation or a larger-than-minimum volume to stay below the 70 °C operating ceiling.
Auxiliaries and communication
Factory-fitted with an undervoltage release (UVR) and a communication module. The auxiliary contact block provides 2 auxiliary switches plus 1 trip alarm and 1 electrical alarm switch (HQ type). The integrated summation ground-fault monitoring uses the L-conductor method. The basic switch assembly is order code 3VA2340-5JQ32-0AA0, and the auxiliary trip module is 3VA9608-0BB25 — useful if you need to order spare sub-assemblies separately.