Interrupting Capacity and Thermal Derating
At 415 V AC the interrupting rating is 52.5 kA, which covers most industrial panelboard fault levels. The thermal derating curve is flat from 40 °C through 50 °C at 50 A, then drops to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. For a panel with an internal ambient of 60 °C — common in a crowded enclosure with multiple breakers — the breaker still holds 48 A continuous, so a 50 A circuit at full load needs a 55 °C or cooler environment or a larger frame.
Power Loss and Operating Conditions
Maximum power dissipation is 9.74 W at rated load — negligible for panel thermal calculations but worth noting in a sealed, uncooled enclosure with multiple breakers. Insulation voltage is rated at 500 V, and the breaker is listed for AC operation up to 415 V and DC up to 250 V.