Which factor is NOT considered when selecting conductor size?

When selecting conductor size for electrical installations, several crucial factors need to be taken into account to ensure safety and efficiency. One of the key aspects of conductor sizing is the current to be carried, as conductors must be able to handle the expected load without overheating or causing damage. Additionally, the distance the electrical current must travel is important because longer distances can lead to voltage drop, necessitating thicker conductors to maintain efficiency.

Ambient temperature also plays a significant role because conductors can carry less current in higher temperatures due to the potential for overheating. Higher ambient temperatures can reduce the ampacity (the maximum amount of electrical current a conductor or device can carry before sustaining immediate or progressive deterioration).

The speed of electrical flow, however, is not a factor considered when selecting conductor size. Electrical signals travel at a significant fraction of the speed of light, which is consistent regardless of the chosen conductor's size. Instead, conductor size is more concerned with how much current can safely flow through the conductor without elevating its temperature to unsafe levels or compromising performance.