This is a Siemens SENTRON 3VA molded case circuit breaker, order code 3VA2340-7JP42-0AA0. 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.
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.
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.