Siemens 3VA2440-6KP32-0AA0 — 400 A MCCB with ETU850, 242 kA at 240 V
The Siemens 3VA2440-6KP32-0AA0 is a SENTRON molded case circuit breaker rated for continuous 400 A across the full 40–70 °C ambient range — no derating needed up to that ceiling. It carries a 242 kA interrupting capacity at 240 V, stepping down to 187 kA at 415/440 V and 121 kA at 500 V, with a 9 kA floor at 690 V. The ETU850 electronic trip unit handles line protection duty with communication capability, making it a fit for main or feeder breakers in LV switchboards where selective coordination matters.
What the ratings mean for your panel
The 400 A rating at 70 °C means this breaker handles full load in a warm enclosure without downsizing — a common pain point with breakers that derate above 40 °C. The 242 kA SCCR at 240 V gives substantial fault-current headroom for transformer-fed services; at 690 V the 9 kA rating still covers most motor-drive branch circuits. The ETU850 release provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves, programmable via the communication interface. Front-side IP40 protection keeps dust out of the panel face; the 248 × 138 × 110 mm footprint (H × W × D) fits standard SENTRON mounting patterns.