What it is and what it does
The Siemens 3VA2340-5HL32-0KA0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous at 40 °C, with three poles and a shunt trip release (STL) for remote tripping. It is designed for line protection — the primary overcurrent and short-circuit safeguard in a distribution panel, not a motor-protective device. Breaking capacity is 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. That 187 kA at 240 V means it can interrupt a fault current up to 187,000 A at that voltage without failing — a high-interrupt rating for heavy industrial service where available fault current is high.
Thermal derating and panel fit
The 400 A rating holds steady from 40 °C up to 50 °C, then derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If the breaker sits in a warm enclosure — say, above a drive or transformer — use the 55 °C or 60 °C column for sizing, not the 40 °C number. Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The 110 mm depth is the body only; allow clearance for the shunt trip wiring and any auxiliary contact block if added later. Mounts on a standard DIN rail or direct-panel via the breaker's own screw terminals.