What this MCCB does and where it fits
The Siemens 3VA2340-7HL32-0JH0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in distribution panels and industrial switchboards. Its 400 A continuous current rating (at 40 °C through 50 °C) and 3-pole design suit it for main feeder or large branch protection in 3-phase systems up to 690 V. Interrupting capacity is 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V — so it can handle high fault currents on the low-voltage side of a transformer, but derates sharply above 500 V. For 690 V applications, verify the available fault current stays under 7.5 kA. Thermal derating starts at 55 °C: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, 340 A at 70 °C. If the panel ambient runs hot, size upstream gear for the derated figure, not the nameplate 400 A.
Dimensions and panel integration
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep. That depth (4.33 in) is the body-only dimension — allow additional clearance for the shunt trip (STL) and the auxiliary switch block (2 aux + 1 trip alarm HQ) fitted as standard on this order code. Power loss at rated current is 96 W maximum. In a sealed, low-ventilation enclosure, that heat has to be factored into the thermal budget — especially if multiple breakers are ganged.