What this MCCB carries and where it fits
The Siemens 3VA2340-5HL32-0CH0 is a 3-pole SENTRON molded case circuit breaker rated for 400 A continuous current at 40 °C, with a maximum breaking capacity of 187 kA at 240 V AC. It is designed for line protection in distribution panels and switchboards, where the interrupting rating at the available fault current is the primary selection gate. The 187 kA at 240 V covers high-fault service-entrance positions; at 415 V it still holds 121 kA, and at 690 V it derates to 7.5 kA — so the voltage class of your bus determines which interrupting rating governs the fit. The unit includes an undervoltage release (UVR) and comes with 2 auxiliary switches plus 1 trip alarm switch (HQ type), which simplifies remote status indication without adding a separate accessory module.
Thermal derating and panel integration
The breaker holds its full 400 A rating up to 50 °C ambient. Above that 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 the panel ambient runs hot — say a packed enclosure with multiple breakers — the 60 °C figure (370 A) is the realistic continuous current for sizing the downstream conductors. The unit measures 248 mm high by 138 mm wide by 110 mm deep, which fits standard MCCB mounting footprints in Siemens SENTRON distribution boards. Max power loss is 98.5 W at rated load, so account for that heat in the enclosure ventilation calculation.