What this MCCB is and what it carries
The Siemens SENTRON 3VA2440-6HN32-0AD0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuously across the full 40 °C to 70 °C ambient range — no derating needed up to that ceiling. It is a line-protection device (not a motor-protection or ground-fault variant), designed to sit in a main feeder or large subfeed position in a 3-phase distribution panel. Breaking capacity is voltage-dependent: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. That 242 kA figure at 240 V makes this breaker suitable for high-fault utility entrance positions in North American 277/480 V wye systems where the line-to-ground fault current can exceed 200 kA. The 9 kA at 690 V is the limit for 690 V line-to-line applications — verify your available fault current against that curve. This variant ships without an undervoltage release, without a ground-fault monitoring module, and without a communication function — it is a pure thermal-magnetic or electronic trip unit breaker (the basic switch order code is 3VA2440-6HN32-0AA0). The auxiliary switch bay is populated with three HQ auxiliary switches, which is a high-quantity configuration for remote status indication on multiple circuits.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. Power loss at rated current is 63.5 W maximum. In a sealed, non-ventilated enclosure, that heat must be factored into the thermal rise calculation — especially if multiple breakers are ganged side by side. The 70 °C maximum operating ambient is the breaker's internal reference; enclosure internal temperature must stay below that.
Lifecycle and sourcing reality
This part carries a current-production lifecycle status. It is an active catalog item in the Siemens SENTRON 3VA2 platform, not a phase-out or last-time-buy SKU. That means factory support, spare parts, and accessory compatibility are all current.