What this 3VA2 SENTRON MCCB delivers on the line
The Siemens 3VA2440-7HL32-0AG0 is a 3-pole molded case circuit breaker from the SENTRON family, rated for 400 A continuous current (Iu) with an ETU320 electronic trip unit. Breaking capacity hits 330 kA at 240 V and 242 kA at 415 V — numbers that matter when you're protecting a feeder feeding a weld line or a compressor bank where fault current is high and you can't afford a cascading failure upstream. The 800 V rated insulation voltage (Ui) means it handles 690 V systems comfortably with margin.
Dimensions and panel fit
At 138 mm wide, 248 mm tall, and 110 mm deep, this MCCB fits standard SENTRON 3VA2 panel cutouts. The 110 mm depth keeps it clear of gland plates on 200 mm deep enclosures — no forced wire bending against the back wall. Spring-cage terminals accept 0.2–2.5 mm² solid or ferruled stranded for the auxiliary wiring.
Trip unit and thermal performance
The ETU320 electronic trip unit provides adjustable overload and short-circuit protection curves. Continuous current holds at 400 A from 40 °C through 50 °C ambient, then derates to 384 A at 55 °C, 376 A at 60 °C, 368 A at 65 °C, and 360 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power dissipation is 63.5 W — factor that into enclosure thermal calcs.