Derating Calculation Info

$$45°C (\textActual) - 25°C (\textRated) = 20°C \text rise$$

In engineering, we apply this concept to: derating calculation

S=β×Sratedcap S equals beta cross cap S sub r a t e d end-sub $$45°C (\textActual) - 25°C (\textRated) = 20°C \text

You have a THHN copper wire rated for 100 Amps . in your specific environment

Derating is not about wasting potential; it is about buying reliability. Spending an extra $0.10 on a higher-rated resistor or capacitor saves $100 in field service calls.

Implementing Power Derating in Practical Applications - Astrodyne TDI

Even though you bought a "500W" power supply, in your specific environment, you can only safely draw 250W .