What does "derating" signify in reference to conductors?

Derating refers to the process of reducing the allowable ampacity of a conductor under specific conditions. Ampacity is the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration. This reduction is necessary to ensure the safe operation of conductors in various environments or situations, such as high ambient temperatures, grouping of multiple conductors, or specific installation conditions that may affect heat dissipation.

When conductors are operated in conditions that could lead to overheating, derating helps to prevent potential problems such as insulation breakdown or fire hazards. By applying derating, electricians and engineers take precautions to ensure that the conductors will operate safely within their limits, thereby maintaining the integrity of the electrical system.