ITC-3: Electrical Load Calculation in Buildings
ITC-3: Classification of Consumption Points
The following classification of consumption points is provided:
- Buildings used primarily for housing
- Commercial or office buildings
- Buildings for a specific industry
- Buildings for a concentration of industries
Electrification and Estimated Power in Homes
The maximum load per household depends on the degree of utilization to be achieved. The following degrees of electrification are established:
Degree of Electrification
Basic Electrification
It is necessary to cover possible needs for primary use without requiring subsequent works. It must allow the use of electrical appliances commonly used in a home.
High Electrification
It is for homes with a projected use of appliances exceeding basic electrification, or anticipation of using electrical heating or air conditioning, or usable areas of housing higher than 160 m2, or any combination of the previous cases.
Prediction of Power
The developer, building owner, or user defines the power to provide according to the supplying company. For new construction, this will not be less than 5,750 W at 230 V in each home, regardless of the power to be contracted by each user, depending on the use of the wiring.
In homes with a high degree of electrification, the power to provide for will not be less than 9,200 W.
In all cases, the power to be provided shall correspond to the maximum capacity of the facility, defined by the rated current of the automatic switch, as indicated in ITC-BT-25.
Total Load for a Building Primarily for Housing
The total load for a building mainly intended for housing is the sum of the load corresponding to housing, general building services, and the load corresponding to commercial premises and garages that are part of it.
The total load for multiple dwellings will be calculated in accordance with the following paragraphs:
Load Corresponding to Housing
It is obtained by multiplying the arithmetic mean of the maximum powers provided in each house by the simultaneity coefficient shown in Table 1 (not provided in the original text) according to the number of dwellings.
For buildings intended for the implementation of a nightly rate, the concurrency will be 1 (simultaneity coefficient = number of households).
Load for General Services
It is the sum of the power provided for elevators, lifting appliances, central heating and cooling, pressure groups, site lighting, staircases, and common areas, and throughout the overall building electrical service, without applying any simultaneous reduction factor (simultaneity factor = 1).
Load Corresponding to Commercial Premises and Offices
It is calculated assuming a minimum of 100 W per square meter of floor space, with a local minimum of 3,450 W at 230 V and a simultaneity coefficient of 1.
Load Corresponding to Garages
It is calculated assuming a minimum of 10 W per square meter of garage floor for natural ventilation and 20 W for forced ventilation, with a minimum of 3,450 W at 230 V and a simultaneity coefficient of 1.
When implementing the NBE-CPI-96, which requires a ventilation system to vent fumes from fire, the load forecasting of the garages must be specifically examined.
Total Load for Commercial/Office Buildings, or for One or More Industries
In general, the power demand will determine the load to provide in these cases, which can never be less than the following values:
Commercial or Office Buildings
It is calculated assuming a minimum of 100 W per square meter of floor space, with a local minimum of 3,450 W at 230 V and a simultaneity coefficient of 1.
Buildings for Industry Concentration
It is calculated assuming a minimum of 125 W per square meter of floor space, with a local minimum of 10,350 W at 230 V and a simultaneity coefficient of 1.
Estimated Loads
The forecast of consumption and loads shall be in accordance with this instruction. The total load under Chapters 2.3 and 4 will be considered in the calculation of the conductors from the connection point and the calculation of bonding facilities.
Single-Phase Supply
Distribution companies are obliged, whenever requested by the client, to make provisions to allow the operation of any single-phase power receiver less than or equal to 5,750 W at 230 V, up to a maximum power supply of 14,490 W at 230 V.