SENTRON 3VA2340-6HL32-0HC0 — 400 A MCCB with Shunt Trip for Line Protection
The Siemens SENTRON 3VA2340-6HL32-0HC0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with a maximum breaking capacity of 242 kA at 240 VAC. The 400 A rating holds flat through 50 °C, then derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C — so in a warm enclosure you lose about 15 % of the headroom by 70 °C.
Breaking capacity varies sharply with system voltage: 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. The 242 kA figure at 240 V gives ample headroom for high-fault service-entrance applications on 240 V delta or 277/480 V wye systems where the line-to-ground fault current can exceed 100 kA.
The 110 mm depth (4.33 in) fits typical 200 mm deep enclosures with clearance for rear-connected busbars. The shunt trip (STL) and two HQ auxiliary switches are factory-installed; no field wiring of separate accessories is needed for basic remote trip and status.
Thermal Management and Power Loss
Maximum power loss is 96 W at rated load. In a sealed enclosure with multiple breakers ganged, that heat must be considered in the thermal budget — a 400 A frame dumping nearly 100 W can raise internal ambient above the 50 °C threshold where derating begins.