The Siemens SENTRON 3VA2440-6KQ42-0AA0 is a 4-pole molded case circuit breaker rated for 400 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal budgeting in a crowded enclosure. Its breaking capacity hits 242 kA at 240 V and still holds 187 kA at 415 V and 440 V, so it handles high-fault utility feeds or transformer secondaries without cascading upstream. The ETU860 electronic trip unit gives adjustable N-conductor protection (OFF, 20% to 130%) and a communication function for integration into a plant monitoring network.
At 415 V and 440 V it still clears 187 kA, dropping to 121 kA at 500 V and 9 kA at 690 V.
Thermal performance and mounting
The 4-pole frame measures 184 mm wide by 248 mm tall by 110 mm deep, which fits standard switchboard cubicle mounting patterns. Maximum power loss is 63.5 W, worth accounting for in enclosure ventilation if you're packing several breakers side by side.