Which condition is not a cause for derating conductors?

Derating conductors is a practice utilized to adjust the ampacity of conductors when certain environmental or installation factors could potentially impact their performance and safety. High ambient temperature, too many conductors in a raceway, and prolonged high usage can all lead to increased heat generation around conductors, which may exceed their rated capacity, thereby necessitating a derating.

In contrast, low voltage in the system does not inherently cause the need for derating conductors. Derating relates directly to the current-carrying capacity and how environmental or load conditions may elevate risks of overheating. Low voltage might affect the efficiency or performance of the electrical system, but it does not directly relate to the thermal impact or physical arrangement of conductors that would require derating to prevent overheating or ensure safe operation. Thus, the presence of low voltage is not a factor that results in the derating of conductors.