What this MCCB carries — and what it means for your panel
The Siemens 3VA2340-7HL32-0DL0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with a 3-pole line-protection configuration and an ETU320 electronic trip unit. The interrupting ratings are the headline here: 330 kA at 240 V, 242 kA at 415 V, and 52.5 kA at 690 V — so it handles fault currents at the main distribution level where upstream transformer capacity is high. The ETU320 gives you adjustable long-time, short-time, and instantaneous protection curves, plus ground-fault alarm capability (though this variant ships without the ground-fault module).
Thermal derating and panel fit
At 40 °C it holds the full 400 A; at 55 °C it derates to 385 A, and at 70 °C to 340 A. That derating curve matters if the breaker sits in a crowded enclosure with other heat sources — plan your ambient around the 55 °C row unless you have forced ventilation. Dimensions are 248 mm high × 138 mm wide × 110 mm deep, which fits the standard SENTRON 3VA mounting footprint; the 138 mm width is three-pole wide, so a 600 mm wide enclosure gives you room for four across plus wiring gutters.
What the ETU320 trip unit does for fault coordination
The ETU320 is an electronic trip unit with LSI protection — long-time (L), short-time (S), and instantaneous (I) — plus adjustable settings for each. That means you can coordinate this breaker downstream of a main 2000 A feeder and upstream of a 100 A branch without nuisance tripping, as long as the time-current curves are set correctly. The 15 000 mechanical endurance cycles are typical for a fixed MCCB at this frame size; it is not a switching device for frequent load-break duty.