Here is how to calculate the maximum demand for a residential or light commercial property using standard diversity factors. Step 1: Group the Loads Divide all electrical equipment into functional categories: General-purpose socket outlets (power points) Cooking appliances (ovens, cooktops) Hot water systems HVAC (Heating, Ventilation, and Air Conditioning) Step 2: Determine Connected Load per Group
If electrical systems were sized by simply adding up the total capacity of every connected appliance—known as the —the resulting infrastructure would be massively over-engineered, unnecessarily expensive, and inefficient. In the real world, a building never runs every light, motor, heater, and appliance simultaneously at 100% capacity. maximum demand calculation
Factors such as grouping, thermal insulation, and ambient temperature can affect the ability of cables to carry the calculated load. Conclusion Here is how to calculate the maximum demand
Cannot be used for completely new greenfield developments. Factors such as grouping, thermal insulation, and ambient
: Always add a 10% to 20% safety margin for future equipment additions.
Sizes cables and transformers correctly. Ensures Compliance: Meets local electrical safety codes. Key Technical Terms
The most fundamental error is to treat connected load as maximum demand. For an office with 100 computers each rated at 300 W, that would be 30 kW, yet the actual maximum demand might be 15 kW because not all computers are drawing full power simultaneously, and monitors have sleep modes.