In a method of wiring, where distance from home run box is critical, how far can cable run from the box to the first luminaire?

In a wiring method where the distance from the home run box to the first luminaire is critical, the maximum allowable distance is often determined by both the technical and regulatory standards set forth in electrical codes. In this case, the distance should not exceed specific thresholds to maintain the integrity and safety of the electrical circuit.

Choosing a distance of more than 8 feet is correct because it aligns with standard practices that allow for adequate voltage drop considerations and the need for efficient circuit design. Exceeding an 8-foot distance helps ensure that any potential voltage drop remains within acceptable limits, which is crucial for the reliability of lighting in spaces where the distance from the power source (home run box) can impact the performance and stability of the luminaire.

In contrast, other distances listed would either be insufficient for most applications or would not adhere to typical requirements used in electrical installations, which generally favor longer runs that still maintain performance standards. Specifically, a limit of less than 7 feet would be impractical in many installations, while exactly 7 feet may not account for all scenarios adequately. More than 10 feet could potentially exceed what is typically recommended in terms of maintaining voltage integrity and could lead to performance issues.