What is the maximum interval for securely supporting vertical runs of metal wireways?

The maximum interval for securely supporting vertical runs of metal wireways is established to ensure safety and compliance with electrical installation regulations. In this case, 15 feet is the correct maximum interval. This requirement exists to prevent sagging and ensure that the wireways maintain their structural integrity over time, minimizing the risk of damage to the wires within and reducing hazards related to electrical failures.

Supporting vertical runs at 15-foot intervals ensures that the wireways are adequately secured, preventing them from shifting or moving under their weight or in response to external forces. Compliance with this interval is essential for maintaining both functionality and safety in electrical installations.

Other intervals mentioned might not meet the necessary safety standards or could lead to increased risks of physical damage to the wireways or the wiring inside them. Thus, adhering to the 15-foot standard supports both safety and reliability in electrical work.