400 A MCCB with ETU320 — what the ratings mean for your panel
The Siemens SENTRON 3VA2340-6HL32-0AG0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) across the 40 °C to 50 °C ambient range, derating to 340 A at 70 °C. The interrupting capacity hits 242 kA at 240 V and 187 kA at 415 V — high enough for most industrial transformer-fed fault-current scenarios without cascading upstream. The ETU320 electronic trip unit handles line protection with adjustable thermal and magnetic curves; no voltage trigger, no undervoltage release, no communication module on this variant. The auxiliary contact package ships as one auxiliary switch plus one trip alarm switch (HP type), so you get remote status without adding a separate module.
Footprint and panel fit
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard SENTRON 3VA frame size for this 400 A class. The 110 mm depth means it clears most 200 mm deep enclosures with room for rear-mounted busbars or a gland plate. No DIN-rail clip; this bolts directly to a mounting plate via the four corner slots. The 96 W maximum power loss at full load needs to be factored into the enclosure thermal budget — don't bury it next to a drive without ventilation.
Environmental and compliance
Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The 800 V rated insulation voltage (Ui) covers 480 V and 600 V class systems with margin. Mechanical endurance is rated at 15,000 cycles — typical for a 400 A frame in distribution duty, not for frequent switching. The SENTRON series carries IEC/UL certifications; compliance documentation (RoHS, REACH, CE, UKCA) is part of the standard delivery package.