Rating and fit — what the numbers mean for your panel
The Siemens SENTRON 3VA2440-6HN32-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current across the full ambient range from 40 °C to 70 °C — no derating curve to chase, per the datasheet. That 400 A holds at every 5 °C step through 70 °C, so it's sized for a warm enclosure without headroom games. Breaking capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. At 415 V, 187 kA means it can interrupt a fault current that high without upstream cascading — relevant for high-fault utility feeds or transformer secondaries. The 9 kA at 690 V is the ceiling; if your system runs 690 V with available fault current above that, this frame won't hold. This MCCB is designed for line protection (cable and busbar protection), not motor or generator protection. It carries an undervoltage release (UVR) as the auxiliary release, and the auxiliary switch complement is 2 auxiliary switches plus 1 trip alarm switch (HQ). No ground-fault monitoring module is fitted — that's a separate add-on if your spec requires it. Physical envelope: 248 mm high, 138 mm wide, 110 mm deep. That 138 mm width is a standard 3-pole MCCB footprint for this frame size — verify your existing busbar spacing and enclosure cutout before committing the BOM line.
Integration and wiring notes
Mounts in a standard MCCB panel footprint. The 3-pole design with 138 mm width fits common busbar systems for this frame class. The undervoltage release (UVR) is factory-fitted — verify coil voltage rating against your control circuit before wiring. The auxiliary switch complement (2 aux + 1 trip alarm HQ) provides status feedback for PLC or annunciator inputs. Maximum power loss is 66 W at rated current — account for that in enclosure thermal calculations, especially in a sealed or high-ambient panel. Storage temperature range is -40 °C to 80 °C; operating ambient is -25 °C to 70 °C. The 5 kA limited to 1 s rating is a short-time withstand figure for selective coordination studies.