What must be applied from Table 310.15(B)(2)(a) when conductors are used in high ambient temperatures?

When conductors are used in high ambient temperatures, correction factors must be applied according to Table 310.15(B)(2)(a). This table provides the necessary adjustments to the ampacity (current-carrying capacity) of conductors to ensure they operate safely and efficiently under conditions that deviate from standard temperature ratings.

High ambient temperatures can increase the likelihood of overheating, which can compromise the insulation and overall performance of the conductors. By applying the correction factors outlined in the table, electrical professionals can determine the appropriate ampacity for the conductors in such conditions, allowing them to select the correct wire size and maintain compliance with safety standards.

This process is essential for preventing potential hazards such as electrical fires or equipment failures due to overheating. Other options like duration factors, install factors, or rating factors do not specifically address the temperature-related adjustments needed for conductor sizing in high ambient environments, making correction factors the appropriate choice for ensuring safe electrical installations.