What this MCCB is and where it fits
The Siemens 3VA2340-6HL32-0BA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current, designed for line protection in distribution panels and industrial switchboards. It carries a maximum breaking capacity of 242 kA at 240 V and 187 kA at 415 V or 440 V, which means it can safely interrupt high fault currents on the secondary side of a large transformer or at a main feeder without cascading upstream. The frame is sized for a 600 A minimum to 4 000 A maximum trip unit range, so this breaker sits at the lower end of the frame's capacity — common for a main or large feeder breaker in a 400 A rated panel.
Breaking capacity across voltage levels
Breaking capacity drops as system 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. The steep drop at 690 V (7.5 kA) means this breaker is not suited for 690 V main feeders in high-fault installations — the frame is optimized for 240–500 V distribution. At 400 V class (common in European industrial panels), 187 kA covers virtually any fault scenario short of a dedicated transformer secondary.
Thermal derating and ambient limits
Rated 400 A continuous from 40 °C through 50 °C ambient. Above that, derating begins: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. If the panel ambient runs above 50 °C, the breaker must be downsized or the load limited per the derating curve — a common oversight in non-climate-controlled enclosures.
Integrated undervoltage release, no auxiliary switch
This variant includes an undervoltage release (UVR) as the auxiliary release, so the breaker trips automatically if control voltage drops below the release threshold — used for emergency stop circuits or undervoltage protection on motor feeders. It ships without an auxiliary switch (no remote status indication) and without ground-fault monitoring. The trip indicator is also absent, so visual confirmation of trip state requires looking at the handle position. If remote signaling or ground-fault protection is needed, a different 3VA variant with those options should be specified.
Physical dimensions and panel fit
Dimensions: 110 mm depth, 138 mm width, 248 mm height. The 138 mm width is standard for a 3-pole MCCB in this frame class — it occupies three modular 45 mm pole spaces on a DIN rail or bolted to a mounting plate. Depth of 110 mm leaves clearance for rear terminals and arc chutes; verify the enclosure depth allows the required bending radius for incoming cables.
Power loss and thermal management
Maximum power loss is 98.5 W at rated current. This heat must be dissipated within the enclosure — for a panel with multiple breakers, the cumulative loss drives ventilation or derating decisions. At 400 A continuous, the 98.5 W loss is typical for a thermal-magnetic MCCB of this frame size.