How is the lighting load determined for multiple incandescent and fluorescent lights?

• A. Based on wattage and amp rating
• B. Based on voltage and hours of operation
• C. Based on total wattage and ballast ratings
• D. Based on fixture quantity and type

Answer: (C)

The determination of the lighting load for multiple incandescent and fluorescent lights is primarily based on total wattage and ballast ratings. Incandescent lights have a specific wattage that dictates their energy consumption, while fluorescent lights require ballasts to regulate the electrical current flowing through them. The ballast's rating is crucial because it affects how much energy the fluorescent fixture actually uses.

When calculating the total lighting load, adding the wattage of all the incandescent bulbs provides a straightforward measurement of their energy demand. For fluorescent lights, the ballast rating is equally important because it can also influence how much power is consumed by the fixtures. Therefore, the total lighting load is calculated by summing the wattage of all incandescent fixtures and the power consumption related to the ballasts of fluorescent fixtures, which accurately reflects the total demand on the electrical system.

In contrast, while other factors like voltage, hours of operation, fixture quantity, and type may impact various aspects of lighting and energy usage, they do not directly measure the load in the same straightforward manner as total wattage and ballast ratings do.