Why is it critical to include lighting load in electrical calculations?

Including lighting load in electrical calculations is essential because lighting contributes significantly to total electrical consumption. In most residential and commercial settings, lighting is a major component of energy usage, often representing a substantial portion of the overall electrical load. Accurately calculating this load ensures that the electrical system can handle the demand placed on it and helps in sizing conductors, overcurrent protection devices, and transformers appropriately to avoid overloads that could lead to system failures or safety hazards.

While it is true that lighting may often be one of the largest components of power consumption in a facility, merely stating that it is the primary source or that it doesn't require a separate circuit does not capture the full scope of its impact on the entire electrical system. Additionally, cost considerations around lighting installations are relevant, but they do not directly relate to the necessity of including lighting loads in calculations. Therefore, prioritizing lighting load in electrical planning safeguards both efficiency and safety in energy distribution.