What this 400 A MCCB delivers in a panel
The interrupting capacity hits 187 kA at 240 V AC, 121 kA at 415 V, and still holds 75.6 kA at 500 V — which means it can clear a high-fault bolted short on a 480 V distribution bus without upstream coordination headaches.
Thermal derating — where the 400 A holds and where it drops
At 55 °C it derates to 392 A, at 60 °C to 384 A, at 65 °C to 376 A, and at 70 °C to 367 A. The TM120M release is fixed-trip; no field-adjustable thermal dial, so the derated current is the hard limit.
Dimensions: 248 mm height, 138 mm width, 110 mm depth. The starter-protection design means it's tailored for motor branch circuits, with the TM120M release curve coordinated for starting inrush.