What this MCCB is and where it fits
The Siemens SENTRON 3VA2340-6KP32-0AH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, designed for line protection in industrial power distribution panels. It carries a 242 kA interrupting capacity at 240 V and 187 kA at 415 V, meaning it can clear high-fault currents on the main feeder without upstream coordination issues. The breaker includes a communication function for integration into a plant monitoring system, and its 138 mm width and 248 mm height fit standard MCCB mounting footprints in switchboards.
Thermal derating — the real current you get
This breaker holds its full 400 A rating from 40 °C up to 50 °C. Above that the thermal curve drops: 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 hot — say next to a bank of drives or transformers — size the upstream conductor and load for the derated value, not the nameplate 400 A. The maximum power loss is 96 W, so enclosure ventilation matters in a sealed cabinet.
Interrupting capacity across voltage levels
The interrupting ratings drop sharply as voltage rises: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V. At 690 V the breaker is essentially limited to low-fault applications — verify the available fault current at the point of installation before specifying it on a 690 V bus.
Auxiliary contacts and basic switch
The breaker ships with 2 auxiliary switches plus one trip alarm switch (HQ design). The basic switch assembly is order code 3VA2340-6KP32-0AA0. There is no undervoltage release or ground-fault monitoring on this variant — if you need those, this is the wrong order code.