What this MCCB does — and what the ratings mean for your panel
The Siemens 3VA2340-6JQ32-0AH0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C through 50 °C, with a 3-pole configuration and an ETU560 electronic trip unit. It is designed for line protection — meaning it sits on the feeder or main in a distribution panel, not on a specific motor or load. The interrupting ratings tell you where it can go: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. Those numbers are the fault current it can safely clear without welding or rupturing — so if your available fault current at the panel is, say, 150 kA at 480 V, this breaker has headroom. The ETU560 is a communicating electronic trip unit, so it can talk to a higher-level system for monitoring and coordination. Let me show you why the thermal derating matters: at 55 °C the continuous rating drops to 375 A, at 60 °C to 350 A, and at 70 °C to 300 A. If your panel ambient runs hot, size the breaker for the actual temperature, not the nameplate 400 A.
Mounting and integration — fits a standard MCCB footprint
This breaker measures 248 mm high by 138 mm wide by 110 mm deep. That depth is the dimension from the mounting surface to the front of the breaker — important when you're planning gland-plate clearance or door clearance in a panel. The width of 138 mm is standard for a 400 A frame in the SENTRON 3VA family, so it will drop into the same mounting cutout as other 3VA breakers of this frame size. The IP40 rating on the front means it's protected against tools and wires greater than 1 mm, but not against water — keep it inside a closed panel.
Trip unit and communications — ETU560 with communication function
The ETU560 trip unit provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves, and it includes a communication function (likely PROFIBUS or PROFINET, though the exact protocol isn't listed in these specs). That communication function lets the breaker report status, trip events, and load current to a PLC or SCADA system — useful for predictive maintenance or remote troubleshooting. The trip indicator is present, so after a trip you can see whether it was a fault or manual operation. The rated insulation voltage is 800 V, which is standard for 690 V systems with margin.