The Siemens SENTRON 3VA2340-5JP32-0BH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) with an ETU550 electronic trip unit. It carries a 187 kA interrupting rating at 240 V, dropping to 121 kA at 415 V and 440 V, and 75.6 kA at 500 V — enough headroom for most industrial main or feeder breakers in a 480 V panel. The 800 V rated insulation voltage (Ui) keeps it comfortable in 690 V systems as well.
What the ratings mean for fit
The 400 A rating holds flat from 40 °C through 50 °C ambient — no derating needed in a typical warm panel. Above 50 °C it steps down: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C. If your enclosure runs hot, that derating curve is the one that decides whether this breaker holds the load or trips prematurely. The ETU550 release is a microprocessor-based trip unit with adjustable long-time, short-time, instantaneous, and ground-fault protection. It also supports communication — the breaker has a communication function, so it can talk to a BMS or SCADA system for remote monitoring and trip-event logging. That makes it a fit for facilities that want power metering and alarm data without a separate CT cabinet. An undervoltage release (UVR) is built in — part number 3VA9608-0BB11 for the integrated auxiliary trip. If your safety circuit needs to drop the breaker on loss of control voltage, that release is already specified. The auxiliary contact block carries 2 auxiliary switches plus 1 trip alarm switch (HQ type), enough for status feedback to a PLC.
Panel fit and integration
The breaker measures 138 mm wide by 248 mm tall by 110 mm deep — a standard SENTRON 3VA frame size for 400 A. It mounts on a DIN rail or directly to a backplate via the fixed lugs. The 110 mm depth leaves room for cable bending radius in a 600 mm deep enclosure. Maximum power dissipation is 98.5 W at rated current. That's the heat you need to vent in the enclosure — factor it into your thermal calculation, especially if the panel is sealed or has other high-dissipation gear.