MCCB with ETU850 — 250 A, 187 kA interrupting capacity
The Siemens SENTRON 3VA2225-5KP32-0JH0 is a 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C, carrying a full 250 A through 50 °C before derating begins at 55 °C (238 A) and stepping down to 200 A at 70 °C. That 250 A frame holds across a wide ambient range — useful in a warm panel where a standard 250 A breaker would already be derated. Interrupting capacity hits 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V — so it handles high-fault utility feeds downstream of a transformer without cascading upstream. Max power loss is 48 W, and latching endurance is rated at 20 000 operations.
The ETU850 trip unit is front-accessible for setting adjustments without removing the breaker from the panel.