This is a Siemens SENTRON 3VA molded case circuit breaker, order code 3VA2340-7JP42-0AA0. It's a 4-pole, 400 A continuous-rated breaker (at 40 °C) with an ETU550 electronic trip unit, built for line protection in distribution panels. The interrupting capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V — so it handles high-fault service entrances and downstream coordination without breaking a sweat. Rated insulation voltage is 800 V, and it carries communication onboard for integration into a monitored system.
What the ratings mean for your panel
The 400 A continuous rating holds at 40, 45, and 50 °C — no derating needed in a typical ventilated enclosure. At 55 °C it drops to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A. If your gear is in a hot mezzanine or unvented cabinet, that derating curve is what decides whether this frame size works or you step up. The ETU550 trip unit gives you adjustable neutral protection — set it OFF or from 20% to 100% of the phase rating. That matters for panels feeding unbalanced loads or where you need to coordinate with downstream GFCI devices. No undervoltage release or ground-fault monitoring on this variant, so if those are spec'd, you're looking at a different 3VA option. Front-face protection is IP40 — fine inside a closed panel, but not for washdown or outdoor exposure without an additional enclosure. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C.
Panel fit and dimensions
The breaker measures 110 mm deep, 184 mm wide, and 248 mm tall. That's a 4-pole frame that needs 7.24 inches of DIN-rail width and 9.76 inches of vertical clearance. No trip indicator on the front, so plan for a separate status indication if your panel requires visual confirmation of tripped state.