What this MCCB carries and where it fits
The Siemens 3VA2340-6HL32-0AD0 is a SENTRON 3VA2 molded case circuit breaker rated for 400 A continuous at 40 °C, with an ETU320 electronic trip unit and three poles. It's built for line protection — the version that sits at the feeder or main breaker position in a distribution panel, not a motor-protection or ground-fault variant. The 242 kA interrupting rating at 240 V (187 kA at 415 V) tells you it can handle high-fault-current service entrances or large industrial switchboards without cascading upstream. At 138 mm wide × 248 mm tall × 110 mm deep, it occupies a standard 3-pole MCCB footprint on a DIN rail or panel-mount base.
Current rating and thermal derating
The 400 A rating holds flat from 40 °C up to 50 °C — that's the full nameplate current without derating in a warm enclosure. Above 50 °C it steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your panel ambient runs above 50 °C, size the breaker for the derated value, not the 400 A label. The maximum power loss of 96 W at rated load means the breaker dissipates heat into the enclosure; account for that in your thermal budget, especially when ganging multiple breakers side by side.
Breaking capacity across voltages
Interrupting ratings are given at five voltage levels: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. The 187 kA at 415 V is the figure most relevant for European 400 V three-phase distribution — it's a high-interrupting-capacity (HIC) class breaker that clears large fault currents without needing a current-limiting fuse upstream. At 690 V the rating drops to 40 kA, still adequate for most 690 V industrial feeders but worth checking against your available fault current.
Trip unit and auxiliary contacts
The ETU320 is an electronic trip unit with LSI protection (long-time, short-time, instantaneous) — adjustable, not fixed. It's the mid-range electronic trip in the 3VA2 family, giving you selectivity tuning without the full metering package of the ETU600. The breaker ships with three auxiliary switches (HQ type) for status feedback to a PLC or panel indication. No undervoltage release, no shunt trip, no ground-fault module are included — those are add-on accessories ordered separately.