Thermal derating and interrupting capacity
The 400 A rating holds flat from 40 °C through 50 °C, then derates linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. That means the breaker can be applied in a 50 °C panel without de-rating the bus — a common condition in enclosed switchgear. Above that, the thermal curve governs; an engineer sizing for a 60 °C ambient should plan for 350 A continuous. Interrupting capacity varies with system voltage: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. At 415 V, the 121 kA figure covers most industrial secondary-distribution fault levels; at 690 V the 7.5 kA rating limits application to lower-fault installations.
Physical footprint: 248 mm height, 138 mm width, 110 mm depth. The 110 mm depth leaves clearance for rear-connected bus bars in a typical 400 mm deep enclosure.
Communication function is integrated, enabling remote monitoring and trip-event logging.
Maximum power dissipation is 98.5 W at rated load.