What is the maximum height of a lighting fixture when supported only by the screw shell of the lamp holder?

The maximum height of a lighting fixture when supported only by the screw shell of the lamp holder is 16 inches. This limitation is essential for ensuring safety and reducing the risk of mechanical failure. When a fixture is solely reliant on the screw shell, which is not designed to bear significant weight, it is crucial to limit its height to prevent strain on the electrical connections.

This 16-inch guideline helps maintain a balance between aesthetics and safety, minimizing the potential for the fixture to loosen or detach due to gravitational stress or vibrations. Following this standard is particularly important in residential and commercial settings to ensure that lighting fixtures operate securely and effectively without hazards.

In contrast, taller fixtures would pose a greater risk of dislodgement or damage, reinforcing the importance of adhering to established height regulations for fixtures that are solely supported by their lamp holders.