What the ratings mean for fit
The Siemens 3VA2340-5JP32-0JA0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous at 40 °C, 3-pole, with an ETU550 electronic trip unit set for line protection. The interrupting ratings tell you where it can go: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so it handles high-fault-current distribution panels without cascading upstream. The 400 A rating holds flat from 40 °C to 50 °C; above that it derates to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. That matters if the breaker sits in a warm enclosure or next to other heat sources.
Panel integration and mounting
Mounts in a standard panel footprint: 248 mm high, 138 mm wide, 110 mm deep. Rated insulation voltage is 800 V. Operating temperature range -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 96 W — factor that into enclosure ventilation if the panel is tight. Latching endurance is 15 000 operations.