What this MCCB carries
The Siemens SENTRON 3VA2440-6HN32-0KH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with the ETU350 electronic trip unit handling the overcurrent protection logic. Breaking capacity hits 242 kA at 240 V and 187 kA at 415 V — that's the short-circuit current it can safely interrupt without welding contacts or venting gas into the panel. The shunt trip release (STL) is built in, and the auxiliary contact block ships as 2 auxiliary switches plus 1 trip alarm switch (HQ configuration).
Current rating and thermal derating
The 400 A rating holds flat from 40 °C through 50 °C. At 55 °C it derates to 384 A, then 376 A at 60 °C, 368 A at 65 °C, and 360 A at 70 °C. If the panel ambient runs hot — say a packed enclosure near a furnace line — the continuous load needs to stay under the derated curve, not the nameplate 400 A. Maximum power loss is 63.5 W, which matters for thermal management in a sealed cabinet.
Breaking capacity across voltages
This MCCB's interrupting rating drops as system voltage climbs: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. For a 480 V panel in North America, the relevant figure is the 121 kA at 500 V — well above typical available fault current in most industrial distributions. At 690 V the 40 kA still covers high-impedance secondary circuits.
Dimensions and panel fit
The 3VA2440-6HN32-0KH0 measures 248 mm high, 138 mm wide, and 110 mm deep. That 138 mm width is a standard 3-pole MCCB footprint for this current class — it fits the same mounting holes and bus-bar spacing as other SENTRON 3VA frames. The 110 mm depth leaves room for rear-connected bus bars or a cable exit box behind the breaker.