How does temperature impact the sizing of feeders?

The correct response highlights that ambient temperature can indeed derate a conductor's ampacity. Ampacity is the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration. As temperature increases, the ability of a conductor to safely carry current without overheating decreases.

When the ambient temperature rises, it can lead to a reduction in the effective current-carrying capacity of the conductors. This means that conductors may need to be larger in size to handle the same amount of current that they could carry at lower temperatures. This is critical during the design and installation of electrical systems, as it ensures safety and efficiency in the operation of electrical systems under varying temperature conditions.

The understanding of this relationship is essential for ensuring that the electrical installations can operate safely and efficiently across different environmental conditions.