Frame rating and interrupting capacity — the numbers that govern selectivity
The Siemens SENTRON 3VA2440-5HN32-0KH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 400 A across the full ambient range from 40 °C through 70 °C — no derating needed up to that ceiling. The interrupting capacity is what drives coordination: 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 9 kA at 690 V. For a panel designer working to IEC 60947-2, the 121 kA at 415 V is the figure that governs upstream breaker selection and downstream cable withstand.
Auxiliary and release configuration — what ships inside the cover
This variant comes factory-fitted with 2 auxiliary switches plus 1 trip alarm switch (HQ), and a shunt trip release (STL). No undervoltage release, no ground-fault monitoring module, no communication function. The auxiliary switch count matters if your BOM calls for feedback to a PLC or status indication on a mimic panel — the HQ trip alarm signals the breaker has opened on fault, separate from the aux switches that track the handle position.
Physical fit — dimensions for panel layout
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep. That 138 mm width is the standard 3-pole MCCB footprint for the SENTRON 3VA2 frame at this rating — it occupies the same panel cutout as other 3VA2 3-pole units, so a panel laid out for a 3VA2116-5HL32-0AK0 will accept this 400 A frame without re-drilling the mounting plate. The 110 mm depth includes the arc-chamber housing; allow clearance for the shunt-trip wiring and auxiliary cable exit at the top.