What this MCCB carries and where it fits
The Siemens SENTRON 3VA2340-6KP32-0AC0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C ambient, with the same rating holding at 45 °C and 50 °C — that's a solid thermal margin for most panel environments. At 55 °C it derates to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A, so you can push it into a warm cabinet as long as you account for the curve. Breaking capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V — that's a high-interrupting frame that handles utility-grade fault levels without cascading upstream. The ETU850 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves — this isn't a thermal-magnetic fixed-trip breaker; you commission it to the load. Communication function is built in, so it talks to your plant monitoring system for power metering and trip event logging. Front face carries IP40 protection — fine for a dry indoor panel, but not for washdown zones. The 2 auxiliary switches HQ give you status feedback to the PLC without an add-on module.
Panel fit and integration
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. That's a standard SENTRON 3VA frame size — it drops into the same mounting footprint as other 400 A 3-pole breakers in the family. No special cutout or adapter plate needed for a typical MCC bucket or distribution panel. Maximum power loss is 96 W — factor that into your panel thermal calculation if you're stacking multiple breakers in a sealed enclosure. Operating temperature range -25 °C to 70 °C; storage range -40 °C to 80 °C. The storage minimum matters if this sits in an unheated warehouse before install.
What the ratings mean for your BOM line
The 400 A continuous rating at 40-50 °C (-) is the headline number for sizing the feeder — it's the current the breaker carries without tripping under normal load. The 242 kA interrupting rating at 240 V tells you it can safely clear a fault at that level; if your available fault current at the panel is lower, you still get the full selectivity benefit downstream. Rated insulation voltage Ui is 800 V — that's the maximum voltage the insulation system is designed for, not the operating voltage. You can use this breaker on 480 V or 600 V systems without derating the insulation. Latching endurance is 15,000 operations — the mechanical life before the mechanism wears. For a main feeder breaker that cycles once a day, that's over 40 years.