Siemens 3VA2450-7HK42-0AA0 — 500 A SENTRON MCCB with ETU340 Trip
The Siemens SENTRON 3VA2450-7HK42-0AA0 is a 4-pole molded case circuit breaker rated for 500 A continuous at 40 °C, carrying the same rating through 50 °C before derating begins at 55 °C (477 A) and stepping down to 410 A at 70 °C. That thermal curve means this breaker holds full ampacity across most common panel ambient conditions — you only lose headroom in a hot enclosure or outdoor cabinet in direct sun. Interrupting capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 9 kA at 690 V. Those numbers place it in the high-fault tier of the SENTRON line — sized for large transformer secondaries or busway feeds where available fault current runs high. The ETU340 electronic trip unit provides adjustable overload and short-time protection with an LSI curve, plus the N-conductor protection can be set to OFF, 50%, or 100% of the phase rating — useful for 4-wire systems where neutral loading varies.
Panel Fit and Deployment
Dimensions are 248 mm high, 184 mm wide, 110 mm deep — a standard SENTRON 3VA2 frame size that bolts into a switchboard or panelboard lineup. Front face carries IP40 protection, so it's suited for enclosed distribution panels where incidental contact is the only exposure. Rated insulation voltage Ui is 800 V, and the operating temperature range spans -25 °C to 70 °C, with storage from -40 °C to 80 °C. Maximum power loss is 99 W — factor that into enclosure thermal calculations if the panel is densely packed.