What this MCCB does and where it fits
The Siemens SENTRON 3VA2340-5HL42-0HA0 is a 4-pole molded case circuit breaker rated for 400 A continuous current at 40 °C through 50 °C, with a line protection design that targets main feeder or large branch-circuit duty in distribution panels. The interrupting capacity hits 187 kA at 240 V and still holds 121 kA at 415 V and 440 V, so it handles high-fault scenarios common in industrial mains without cascading upstream. A shunt trip release (STL) is built in for remote tripping; there is no undervoltage release and no auxiliary switch on this variant. The 110 mm depth and 184 mm width fit standard MCCB panel cutouts — check the 248 mm height for enclosure clearance.
Thermal derating and real-world current
The 400 A rating holds flat from 40 °C to 50 °C ambient. Above that, it steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If the panel ambient runs hot — say a non-conditioned electrical room in summer — size the load at the derated figure, not the nameplate 400 A. Maximum power loss is 96 W, which matters for ventilation planning in a sealed enclosure.
Interrupting capacity by voltage
The 3VA2340-5HL42-0HA0 delivers 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. The steep drop at 690 V means this breaker is not the right choice for a 690 V main where fault current exceeds 7.5 kA — step up to a higher-rated SENTRON frame for that. For 400 V class systems (common in North American 480 V and European 400 V), the 121 kA covers virtually all utility transformer secondary faults.
Integration notes
Mounts in a standard MCCB panel cutout. The 4-pole design requires neutral conductor termination on the fourth pole — verify the panel bus bar arrangement supports a 4-wire feed. The shunt trip release needs a separate control voltage source; wire per the terminal diagram on the breaker label. No communication function or ground-fault monitoring on this variant, so external relays or a separate GFCI breaker would be needed for those functions.