The use of the 100' tap rule is limited to installation in high-bay manufacturing buildings with wall heights over what measurement?

The 100' tap rule is a guideline in the National Electrical Code that allows for the use of a longer tap conductor in certain installations, specifically in high-bay manufacturing buildings. This rule is designed to provide flexibility in the placement of electrical feeders and branch circuits in spaces where the height of the building may pose unique challenges for installation and accessibility.

In this context, the correct answer indicates that the 100' tap rule is applicable in buildings that have wall heights exceeding 35 feet. This height is significant as high-bay manufacturing environments often require specific electrical configurations that accommodate large equipment and the operational needs of the facility. By setting the threshold at over 35 feet, the code acknowledges the unique nature of these environments and allows for a practical approach to installing electrical systems in high-ceiling locations.

When the wall height extends beyond this measurement, it typically implies a more complex electrical system that necessitates careful consideration of wire lengths, voltage drop, and accessibility for maintenance. Thus, the 100' tap rule serves to streamline electrical installations while ensuring safety and compliance with building standards in such specialized settings.