What this MCCB delivers — and what the ratings mean for your panel
The Siemens SENTRON 3VA2340-5HL32-0HL0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with a rated insulation voltage of 800 V. This is the line-protection version — no ground-fault monitoring, no communication module, no undervoltage release — built for straightforward feeder or main-switch duty in distribution panels. Breaking capacity is the headline: 187 kA at 240 V, 121 kA at 415 V, 121 kA at 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. At the common 415 V industrial level, 121 kA means this breaker can safely interrupt a fault current that high without upstream fuses or a current-limiting reactor — a real advantage on high-capacity transformer secondaries or near large motor banks. The ETU320 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection (though the ground-fault function is not wired on this variant). Thermal derating is published: full 400 A up to 50 °C, then 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 hot, factor that in at the design stage. Auxiliary contacts are fitted as 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch (HQ type), plus a shunt trip (STL) for remote opening. The integrated auxiliary trip is order code 3VA9688-0BL30. There is a voltage-trip indicator and a mechanical trip indicator — useful for quick fault diagnosis on the floor.
Panel fit and integration
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is standard for a 3-pole frame at this rating — it fits the usual MCCB cutout in distribution panels. No DIN-rail mounting; it bolts directly to the panel backplate or onto a mounting plate. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 96 W — account for that heat in the enclosure sizing if the breaker is enclosed.