Which factor is least likely to affect the choice of conduit size?

The choice of conduit size is influenced by several key factors, including the length of the cable run, the type of electrical installation, and the number of conductors being used. Each of these elements directly impacts the needed space within the conduit to accommodate the wiring and ensure safety and compliance with electrical codes.

Installer's personal preference, however, is least likely to affect the choice of conduit size in a technical and regulatory context. While installers may have preferences for certain types or sizes of conduits based on their experiences or habits, the decision regarding conduit size must primarily adhere to standardized guidelines, regulations, and the technical requirements dictated by the project. The choice has to meet specifications related to safety, heat dissipation, and conductor capacity, which are not subjective to personal preferences. This makes personal choice significantly less relevant compared to the other mentioned factors that directly affect the functionality and safety of the installation.