The Siemens SENTRON 3VA2440-7HL32-0AJ0 is a 3-pole molded case circuit breaker rated for 400 A continuous current across its full ambient range of 40 °C to 70 °C — no derating needed up to the top of that band. That flat thermal curve is the headline feature for panel builders: it simplifies coordination in a warm enclosure where other breakers would force a frame size bump. The adjustable instantaneous trip range spans 600 A to 4800 A, letting you dial in selectivity with downstream devices without swapping the breaker. At 240 V the interrupting rating hits 330 kA; at 415 V and 440 V it holds at 242 kA, dropping to 187 kA at 500 V and 9 kA at 690 V. Maximum power loss is 63.5 W — relevant for thermal management inside a sealed panel. The base order code is 3VA2440-7HL32-0AA0; this -0AJ0 variant adds the specified auxiliary contact package.
The depth of 110 mm (4.33 in) is compact enough for shallow backpanel layouts; verify gland-plate clearance against the 248 mm height when mounting in a row with other breakers. The 70 °C operating ceiling matches the top of the flat derating curve, so the breaker delivers its full 400 A even in a hot enclosure near the top of a panel.