What this 400 A MCCB delivers
The Siemens SENTRON 3VA2340-5HL42-0JC0 is a 4-pole molded case circuit breaker rated for 400 A continuous current at 40 °C through 50 °C without derating — it holds full rating across the typical switchroom ambient band. At 55 °C it still delivers 385 A, at 60 °C it gives 370 A, and at 70 °C it provides 340 A, so you can place it in a warmer enclosure or near other heat sources and still get useful capacity. Breaking capacity reaches 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — the 415 V figure is the one that governs for most 400 V-class industrial distribution, and 121 kA covers nearly any fault level you will see downstream of a utility transformer. This is a line-protection design (not a motor-protector or feeder switch), so its trip curve and thermal-magnetic or electronic characteristics are tuned for cable and busbar protection. It ships with a shunt trip (STL) release and two HQ auxiliary switches built in — the shunt trip lets a remote signal or safety circuit force the breaker open, and the auxiliary switches report position back to a PLC or status lamp. The supplied basic switch is order code 3VA2340-5HL42-0AA0, meaning the frame and internal mechanism match that base variant; the -0JC0 suffix adds the specific release and accessory configuration. Maximum power loss is 96 W, which matters for enclosure thermal calculations if you are packing multiple breakers in a small cabinet.
Panel fit and mounting
The breaker measures 184 mm wide, 248 mm tall, and 110 mm deep. That 110 mm depth is the dimension that governs how much clearance you need behind the panel door — it fits standard 400 A frame MCCB footprints, so it will drop into existing SENTRON 3VA cutouts without re-drilling the mounting plate. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.