What this MCCB does and what the ratings mean
The Siemens SENTRON 3VA2340-5HN32-0KA0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C, with a maximum rated current of 4 000 A. It interrupts fault currents up to 187 kA at 240 V, 121 kA at 415 V, 121 kA at 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — so at typical 400 V distribution voltages it clears a 121 kA bolted fault without cascading upstream breakers. The shunt trip release (STL) allows remote tripping from a PLC or emergency-stop relay, which is standard for a line-protection MCCB in a motor control center or main switchboard.
Thermal derating and panel integration
At 55 °C the continuous rating drops to 385 A, at 60 °C to 370 A, at 65 °C to 355 A, and at 70 °C to 340 A. The unit measures 138 mm wide, 248 mm tall, and 110 mm deep — a standard 3-pole MCCB footprint that fits a fixed-mounted or draw-out cradle in a SENTRON LV switchboard. The maximum power loss is 96 W, so adjacent breakers need spacing or forced ventilation in a sealed enclosure.