New York State Master Electrician Practice Exam

When can lights be installed in ducts or plenums used for environmental air?

1. Open type lighting

2. Sealed types only

3. Enclosed gasket type

4. Only with motion sensors

The correct answer is: Enclosed gasket type

The use of enclosed gasket-type lighting fixtures in ducts or plenums that are utilized for environmental air is permitted because these fixtures are designed to prevent the passage of air and contaminants, ensuring that they do not compromise the air quality. The enclosed design minimizes the risk of dust, moisture, and other particles entering the light fixture, which is critical in spaces where air is circulated throughout a building. Additionally, this type of lighting provides a safe solution that complies with various codes regulating the installation of electrical equipment in air-handling spaces. The gasket ensures that the fixture is sealed properly, mitigating potential safety hazards such as overheating or electrical shorts due to exposure to air flow and debris. Open type lighting fixtures or sealed types may not provide the necessary protection and containment required for installations in ducts or plenums. Similarly, the condition regarding motion sensors does not directly address the suitability of light fixtures for these sensitive air-handling environments. Thus, the enclosed gasket type lighting is the most suitable option for installation in this context.