Dwelling Interior Electrical Installation: Circuits, Distribution, and Grounding

Interior Electrical Installation of a Dwelling

The number of circuits depends on the degree of electrification. It consists of:

Overview of the Distribution Board

Located at the beginning of the indoor facility, it is equipped with protective devices against overloads, short circuits, and indirect contacts. It includes:

• Automatic Switch (IGA): Cuts and connects all active conductors, providing protection against overloads and short circuits.
• Differential Circuit Breaker: Protects against indirect contact.
• Miniature Circuit Breakers: Protect each of the housing circuits.
• Power Controller: A measuring and control device (not protective) required by the supplier to ensure power consumption does not exceed the contract.

Distribution of Points of Use

Follows the Low Voltage Electrotechnical Regulations.

Conductors

Usually made of copper with insulation rated for 750V (or 440V), either rigid or flexible. Cable sections must meet minimum requirements. Conductors are identified by color: phase (black/brown), neutral (blue), and ground (green/yellow).

Installation Systems

The most common system uses insulated conductors within recessed tubes. These tubes are defined by their nominal inside diameter, and their installation follows general rules.

Electricity Rates

Consists of a billing term for energy consumed and a billing term for the power controller. Equipment rental, taxes, time discrimination, etc., are added. The market was liberalized in 2003, and since 2009, users can choose their electric service provider. The government provides a last resort supply for those unable to hire a marketer. There is a supplement for reactive power, which includes a bonus based on the power factor.

Facilities Bond

This connects the distribution network of the electric power supply company to the facilities inside a building. It includes the following:

• Riser: The part of the installation linking the distribution network and the general protective housing. It can be single or three-phase, aerial or underground.
• General Protection Box: A box containing fuses that protect the line from the supplier.
• Supplier Line: Overall housing protection that leads to referrals for each of the conductors.

Counters

Located at the beginning of each derivation for subscribers, they can be individual or concentrated. Their operation is based on a rotating disk, with rotation proportional to energy consumption. There are active and reactive energy counters, some of which discriminate based on the time of day. They can be single or three-phase.

Single-Lead

These connect each subscriber's counter with private control and protection devices.

Grounding

A circuit designed to ground overvoltages. Its elements are:

• Grounding Rods: Ground electrodes connected to the earth and grounding points.
• Main Ground Lines
• Derivations of the Main Ground Lines

Power in a Building

Homes have different degrees of electrification or load, depending on the housing surface and/or type of receptors. Minimum: 3000W, Medium: 5000W, High: 8000W, Special: >8000W. A simultaneity coefficient must be applied for a residential building. The total power of a building for housing will be: Pe = Pv + Pg + Pc