What this MCCB carries and where it fits
The Siemens SENTRON 3VA2340-5HN42-0KC0 is a 4-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with the ETU350 electronic trip unit handling overcurrent protection. Its 187 kA interrupting capacity at 240 V means it can safely clear a fault of that magnitude without upstream devices needing to coordinate — useful for high-fault panels close to a transformer or generator bus. At 415 V and 440 V it still holds 121 kA, dropping to 75.6 kA at 500 V and 7.5 kA at 690 V, so the voltage class drives the real SCCR headroom you design around. The 800 V rated insulation voltage (Ui) confirms it's built for 690 V line-to-line systems with margin. Rated 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 number — the 400 A nameplate is only valid up to that point. The -25 °C to 70 °C operating range covers most indoor industrial environments, and the IP40 front protection keeps dust out of the enclosure face.
Panel integration and footprint
The breaker measures 184 mm wide, 248 mm high, and 110 mm deep. That 184 mm width for a 4-pole frame is standard for SENTRON 3VA2 breakers — it'll drop into existing panel layouts designed for that footprint. No communication function onboard; this is a standalone protection device, not a networked power monitor. It carries two HQ auxiliary switches for status feedback to a PLC or annunciator panel.