how is the total lighting load in amperes determined

To design an electrical system for a building, one of the critical components is determining the total lighting load in amperes. The total lighting load is the total electrical power consumed by all the lighting fixtures in the building. The electrical engineer needs to understand the various factors that contribute to lighting loads and how to accurately calculate them. In this article, we will explore the methods and formulas used to determine the total lighting load in amperes.

Factors affecting the lighting load

The total lighting load in a building is influenced by several factors, including the type of lighting fixtures, the number of luminaires, the size of the space, and the lighting control system. Incandescent bulbs consume more energy in comparison to LED lights, and the number of luminaires installed also affects the lighting load. The size of the space, whether it is a home or a commercial building, plays a role in the lighting load, and lighting control systems such as occupancy sensors, daylight sensors, and timers can reduce the total load.

Calculating the lighting load

To calculate the total lighting load in amperes, we use the formula:Total Lighting Load (Ampere) = Power Consumption (Watts) / Voltage (Volts)The power consumption is the total wattage consumed by all the lighting fixtures in the building, and the voltage is the electrical potential difference measured between two points in a circuit. For example, suppose a building has 100 LED bulbs, each consuming 10 watts, and the voltage running through the circuit is 120 volts, the total lighting load would be:Total Lighting Load (Ampere) = (100 x 10) / 120Total Lighting Load (Ampere) = 8.33 ATherefore, the total lighting load for our example is 8.33 Amps.

Load calculation by space

Sometimes we need to calculate the total lighting load per space, such as a single room or a floor in a building. To calculate the lighting load per space, we use the same formula but add a factor of 'Square Footage' (SqFt). Total Lighting Load per Space (Ampere) = (Power Consumption x Square Footage) / VoltageSuppose we have a room with an area of 250 sq. ft. and ten LED bulbs, each consuming 5 watts, and the voltage is 120 volts, the total lighting load per space would be:Total Lighting Load per Space (Ampere) = (10 x 5 x 250) / 120Total Lighting Load per Space (Ampere) = 10.42 ATherefore, the total lighting load per space in our example is 10.42 Amps.

Conclusion

In conclusion, the total lighting load in amperes is an essential factor to consider when designing the electrical system of a building. The calculation considers factors such as the type of lighting fixtures, the number of luminaires, the size of the space, and the lighting control system. The formulas used to calculate the total lighting load and the load per space are simple, and they provide valuable information in helping electrical engineers design an efficient and cost-effective electrical system for a building.