NEC Commercial Electrical Practice Test

How far below the normal water level must underwater lighting fixture lenses be installed in swimming pools?

1. 12 inches

2. 18 inches

3. 24 inches

4. 30 inches

The correct answer is: 18 inches

Underwater lighting fixture lenses must be installed at least 18 inches below the normal water level in swimming pools to comply with safety standards set forth in the National Electrical Code (NEC). This requirement is established to minimize the risk of electrical shock to swimmers and to ensure that the lighting fixtures are adequately submerged to function properly. Maintaining this distance helps prevent potential water-related hazards, as it ensures that the fixtures are less likely to be affected by surface disturbances, such as splashes or wave action. Additionally, positioning the lenses at this depth offers better light diffusion and visibility, enhancing the overall illumination of the pool area. Understanding this requirement is crucial for both safety and compliance with electrical codes, ensuring that installations meet necessary guidelines for safe operation in aquatic environments.