Line protection MCCB with ETU320 — 400 A frame, 242 kA at 240 V
The Siemens SENTRON 3VA2440-6HL32-0AD0 is a 3-pole molded case circuit breaker rated for line protection, carrying 400 A continuous current (Iu) with an ETU320 electronic trip unit. The 242 kA breaking capacity at 240 V gives serious fault-current headroom for high-capacity distribution — that rating covers most industrial service-entrance and feeder applications without needing a current-limiting upstream device. At 415/440 V it still holds 187 kA, and at 690 V it's 40 kA, so the part scales across voltage levels without swapping frames. Rated insulation voltage Ui is 800 V, meaning the internal clearances and creepage are designed for 690 V systems with margin. The ETU320 release offers adjustable thermal-magnetic or electronic protection curves depending on configuration — this is the same trip platform used across the 3VA2 frame family, so settings and accessories carry over.
Thermal derating and panel fit
The 400 A rating holds flat from 40 °C through 50 °C ambient — no derating needed in a typical 40 °C panel. At 55 °C it drops to 384 A, at 60 °C to 376 A, and at 70 °C to 360 A. If the enclosure runs hot (stacked breakers, poor airflow), the 55 °C and above figures are the ones to size against, not the 400 A nameplate. Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The 110 mm depth is shallow enough for most 400 mm deep enclosures with gland plate clearance. Three auxiliary switches (HQ type) are integrated — no separate add-on block needed for status feedback to a PLC or SCADA.