What is a common reason for derating conductors in conduit?

Derating conductors in conduit is commonly done due to high temperatures. When conductors carry electrical current, they generate heat. If the operating temperature exceeds the rated limit of the conductors, it can lead to insulation failure, reduced lifespan of the conductors, and potential safety hazards such as fire. Thus, in scenarios where the ambient temperature is elevated, or when conductors are bundled together, it becomes essential to derate them—meaning to reduce their allowable current-carrying capacity. This ensures that the conductors operate within safe temperature limits, maintaining their integrity and safety over time.

In contrast, low load, distance, and voltage fluctuation do not typically necessitate derating conductors in the same way. Low load may actually suggest that it is safe to use the full capacity of the conductors. Distance might influence voltage drop calculations, but it does not directly relate to the overheating issue. Voltage fluctuations can affect system stability, but they also don't directly warrant derating in the context of thermal management.