Which of the following reflects a correct ampacity calculation for three current-carrying conductors?

To determine the correct ampacity calculation for three current-carrying conductors, it’s essential to understand the concept of ampacity and how it is affected by the number of conductors. The ampacity is the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration.

When there are multiple current-carrying conductors bundled together, the ampacity must be derated according to specific code rules. The factors used for derating depend on the number of conductors and their configuration. For three conductors, a common derating factor might be 0.58, reflecting how the heat generated by multiple conductors impacts their overall performance.

In the correct calculation where 225 A is the original ampacity, applying the 0.58 derating factor correctly utilizes the formula:

225 A * 0.58 = 130.5 A

This reflects the effective ampacity that can be safely used under the conditions presented.

In contrast to the other calculations, those reflect either original ampacity values or different derating factors which may not appropriately represent the derating applicable for three conductors or may apply to different scenarios. For example, if the original ampacity or the derating factor is incorrect, the