What it is and where it fits
The Siemens 3VA2340-6HL32-0LB0 is a SENTRON molded case circuit breaker (MCCB) rated for line-protection duty — meaning it's the primary overcurrent protective device between a transformer or feeder and a distribution bus, not a motor-circuit protector. It's a 3-pole unit with a continuous current rating of 400 A, and it holds that rating all the way up to 50 °C ambient. At 55 °C it derates to 385 A, at 60 °C to 370 A, at 65 °C to 355 A, and at 70 °C to 340 A — so if your panel runs hot, you need to account for that thermal curve. The overload trip setting is adjustable between 600 A and 4,000 A — that's a wide band, so it can be tuned to the actual load without swapping the breaker body. The interrupting ratings are serious: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V. At 690 V the number drops sharply, so if you're on a 690 V system verify the available fault current is under that threshold.
Built-in control and signalling
This breaker ships with an undervoltage release (UVT) and a universal trigger (UNI) auxiliary release, plus two auxiliary switches (HP type). The UVT means the breaker trips automatically if control voltage drops — standard for safety disconnects on emergency-stop chains or undervoltage protection schemes. The auxiliary switches give you remote status: open/closed indication back to a PLC or annunciator panel. No communication module onboard (no PROFIBUS, no Modbus), so if you need remote trip data you'll wire the aux contacts into an I/O block. Dimensions are 248 mm high, 138 mm wide, 110 mm deep — standard 3-pole MCCB footprint for this class. Panel cutout and mounting hole pattern match the SENTRON 3VA2 family. The power loss at rated current is 98.5 W, so factor that into enclosure thermal calculations.
Lifecycle and sourcing
Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. That covers most indoor industrial environments, including unheated warehouses in cold climates.