400 A MCCB with shunt trip — what the ratings mean for the panel
The Siemens SENTRON 3VA2340-6JP32-0HA0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C ambient — that's the full-load current it carries without tripping on a warm panel day. The thermal derating curve is published: it holds 400 A through 50 °C, drops to 375 A at 55 °C, and steps down to 300 A at 70 °C, so if your enclosure runs hot, size the breaker for the actual ambient, not the nameplate. Breaking capacity is voltage-dependent: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V. That tells you the fault current it can safely interrupt at each voltage level — critical for SCCR coordination downstream. At 690 V the 7.5 kA figure means this breaker is not your first choice for 690 V distribution unless the available fault current is known to be low. It ships with a shunt trip release (STL), so you can remotely trip the breaker via a control signal — useful for emergency-stop circuits or interlocking with a fire-alarm panel. No undervoltage release, no ground-fault monitoring, no auxiliary switch on this variant. Communication function is present, which means it can talk to a higher-level system for metering or remote status.
Panel fit — dimensions and mounting
Physical envelope: 110 mm deep, 138 mm wide, 248 mm tall. That's a standard SENTRON 3VA frame size for a 400 A 3-pole MCCB. Mounts on a DIN rail or directly to a backplate via the breaker's own mounting lugs. Verify the cutout and bus-bar spacing against your existing panel layout before ordering.