What this MCCB carries — and what it means in the panel
The Siemens SENTRON 3VA2340-5HL32-0HC0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C, with a breaking capacity of 187 kA at 240 V AC. That 187 kA figure is the maximum interrupt rating at the lowest voltage — it tells you this breaker can clear a bolted fault on a high-capacity 240 V bus without the arc re-striking. At 415 V and 440 V it still holds 121 kA, and at 500 V it's 75.6 kA. The 7.5 kA at 690 V is the floor; if your system voltage sits there, the breaker still clears but the fault current available must be below that threshold. This is a line-protection device — meaning it's designed for feeder and main breaker duty, not motor branch-circuit protection. The continuous current holds flat at 400 A from 40 °C through 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 your panel ambient runs above 50 °C, size the breaker for the derated value, not the nameplate 400 A. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. That covers most indoor industrial environments, including unheated warehouses and hot MCC rooms. The max power loss is 96 W — account for that in your panel thermal budget if the breaker is enclosed in a small cabinet with other heat sources.
Built-in accessories and what they do for commissioning
This variant ships with a shunt trip release (STL) and two HQ auxiliary switches. The shunt trip lets you remotely trip the breaker from a PLC or emergency-stop circuit — useful for a controlled shutdown on a conveyor or kiln feed. The two auxiliary switches provide status feedback (open/closed/tripped) to the control system without needing external limit switches. No undervoltage release is fitted; if you need UVR protection, that's a different variant. The breaker has a voltage trigger (shunt trip) but no trip indicator and no communication function. It's a standalone device — no Modbus or PROFIBUS module inside. For remote monitoring you'd add an external I/O block reading the auxiliary contacts.
Footprint and panel fit
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. That's a standard SENTRON 3VA2 frame size. Mounts on a DIN rail or direct panel-mount via the rear slots. The 138 mm width means it occupies three 45 mm pole spaces on the rail — verify your enclosure clearances, especially if you're retrofitting into an existing panel that was dimensioned for a different brand.