Electrical wiring diagrams in a private house: rules and design errors + nuances of electrical wiring

The electrical supply diagram of a private home is a lot of organized cables, wires, and protective devices. The correct selection of parameters and characteristics of the circuit elements guarantees the safety and comfort of property owners.

If the circuit is drawn up correctly, taking into account the requirements of the PUE and other regulatory documents, there is nothing to fear - there will always be light and warmth in the rooms, and electrical appliances will not break due to power surges or short circuits in the network. Therefore, special attention should be paid to electrical design.

We suggest you understand all the intricacies of this process. The article outlines the general requirements for designing an electrical network, provides practical advice on choosing wires, and also discusses in detail typical electrical wiring diagrams.

In addition, we have prepared a review of common mistakes, taking into account which will help to avoid shortcomings in the development and installation of power supply networks.

General rules for electrical network design

When there were few electrical appliances, and several 40-60 W light bulbs were enough for lighting, a primitive circuit was drawn up to set up the power supply system, including several switches and sockets.

Now, with the advent of a large number of energy-dependent household appliances, the circuit is necessarily differentiated into group lines protected by circuit breakers and other devices.

In just one kitchen, up to a dozen devices can be connected, 2-3 of which are powerful units that require dedicated power lines with a larger cross-section cable and separate sockets

If you think through all the nuances of the location of electrical wiring in a private house, taking into account the use of copper wire, it will last at least 20 years. Typically, a diagram is drawn up along with the design of a new house or before a major renovation.

You should start by indicating the installation locations of such elements as:

• sockets;
• switches;
• distribution boxes;
• lighting devices;
• powerful household appliances;
• electrical panel

At the same stage, you should decide on the method of laying the cables - open or closed. In houses with plastered walls, a closed method is usually used; in houses with wooden walls, an open method is used.

Whatever scheme you use, there are a number of rules that you cannot deviate from. They are prescribed in regulatory documentation, and their effectiveness has been proven for decades.

Here are a few important axioms of electrical installation that will be required to draw up a diagram:

In addition to the rules, personal comfort should also be taken into account. For example, a double bed usually has two sockets installed - one on each side.

Switches are located at a height of 80-90 cm from the floor. In large halls, corridors, rooms install pass-through switches.

To save energy, LED lights with motion sensors are installed on the stairs leading to the second floor or attic, which turn on only in the presence of a person.

Be sure to ground all metal outlets and objects connected to power lines. For grounding in electrical installations, the third core of the cable is used - a wire in yellow-green insulation.

Recommendations for choosing wires

In houses made of brick, aerated concrete blocks, and cinder blocks, interior wall decoration is required, which means that a hidden method is used for laying wires.

To provide additional protection, and in case of repair to quickly replace the cable, it is placed in corrugated sleeve non-flammable polymer.

In houses made of timber or rounded logs, to preserve the retro style, they use an open method of laying wires, purchasing decorative products - twisted wiring, rollers, stylized switches and sockets

To get it right select the wire cross-section, specialists make calculations related to determining the load.

However, based on standard diagrams and many years of experience, qualified electricians adhere to the following parameters:

• lighting circuits – 3*1.5 mm² or 3*2 mm²;
• socket groups – 3*2.5 mm²;
• electric stove/oven – 3*4 mm²;
• air conditioner – 3*2.5 mm², for devices more powerful than 5 kW – 3*4 mm²;
• heating boilers – 3*4 mm² or more (according to the manufacturer’s recommendations).

The optimal type of cable is three-core copper: VVGng, ShVVPng. It is impossible to use wires with a cross-section smaller than the specified one, as they will not match the load and will begin to melt, creating a dangerous situation.

Analysis of electrical wiring diagrams

Let's look at several typical schemes that are used during construction or major repairs. All options are united by the presence of a protective group: dividing the electrical wiring into circuits, each of which is connected to a separate circuit breaker.

Option #1 – general plan for the whole house

This is not a wiring diagram, but a listing of all electrical devices that are planned to be located in the house. Using it you can calculate how many machines you will need and RCD, count the total number of power lines leading to the switchboard.

Here you should indicate the type of power supply network in order to select the correct cable. For a 3-phase network, use a 5-wire cable, for a 1-phase network, use a 3-wire cable.

The organization that supplies electricity to the house is responsible for some of the devices. This is an electric meter and input protection device, which is usually installed on the outer wall of the house or on a pole supplying the cable (+)

The electrical panel is located in a separate room inside the house, in the hallway, or in the nearby garage. Voltage stabilizers and a backup generator are also installed there, which supplies the house with electricity during periods when the centralized line is disconnected.

For ease of maintenance of a two- or three-story mansion, each floor also installing an electrical panel. All distribution boards are connected to an input cable - copper wire with a cross-section of 15-35 mm².

There is no need to skimp on protection devices: it is recommended to install an RCD on each socket circuit, circuit breakers on the light lines for each room, as well as for air conditioners, heating boilers, underfloor heating systems, etc.

If you plan to place several lamps and sockets in a separate room, then you need to install junction box. It connects the input cable to the lighting line and socket group.

Option #2 – sample wiring diagram

To draw a wiring diagram, you need to take a house plan and mark on it where electrical devices will be installed.

This document becomes the basis for drawing up an estimate - it is easy to use it to count not only the number of switches, sockets and additional materials, but also to calculate the footage of wires.

Wiring diagram of the electrical network of a one-story house. To make it easier to navigate the electrical lines leading from the electrical panel to the rooms, the contours are marked in different colors

The point of entry of the power line into the house and the installation location of the electrical panel must be indicated. Then, on separate lines, distribution boxes, electrical installations, and lighting fixtures should be noted.

High power devices also need to be labeled as they are powered by individual lines.

If outbuildings are connected to the building - a bathhouse, a garage, a workshop - this should also be reflected in the diagram, since it is part of the electrical wiring in a particular private house.

There are no special symbols for hand-drawn diagrams; the main thing is that the home owner and installers understand what lies behind each symbol. However, it is better to use common designations for electrical circuitsso that you can understand the project yourself later.

Option #3 – technical solution for a small house

All plans and diagrams are similar, since they are built on the same principle, but they may differ in the number of installed sockets and lighting circuits, and, consequently, in the number of protective devices connected to them.

A sample diagram for a one-story house, inside of which there are 3 rooms, a corridor, a kitchen, and a bathroom. The power lines are assembled so that one of them connects the corridor and the room, the second - 2 rooms

An input switch is installed in front of the network, which, if necessary, can be used to de-energize the entire house and turn off the electricity meter. Then comes the counter, and after that comes the protective groups.

For powerful units, such as a heating boiler or a washing machine, 25-40 A machines are installed. The wire cross-section should also be increased to 3.5-5 mm².

Using such a diagram, it is not possible to calculate the footage of wires, but the number of sockets, distribution boxes, switches, RCDs, and automatic circuit breakers is easy to calculate.

Option #4 – electrical circuit for the basement/garage

Often, the basement of a private house becomes a utility room where a washing machine is installed and a dryer is equipped, a cellar for storing crops, or even a warm garage. It is much more convenient when such a room is fully equipped with sockets and lamps.

The diagram shows the wiring of the electrical network with an electricity meter. If the garage is located in the basement or in an extension, a separate meter is not needed

If you do not take into account the meter, the electrical panel will remain with input circuit breakers, a grounding bus, a 20 A RCD, three circuit breakers: on the lighting line, for sockets and for the compressor.Additional powerful equipment also requires automatic protection.

Option #5 – principles of kitchen wiring

Scheme electricians for the kitchen in a private house is practically no different from a similar scheme for a city apartment.

Its peculiarity is a large number of connected electrical appliances, therefore, it will be necessary to allocate several power lines with separate circuit breakers.

The main difficulty is placing the socket blocks so that they are close to the devices and at the same time freely accessible for possible repairs or switching of devices (+)

When drawing up a vertically oriented diagram, it is necessary to display on paper a furniture set with the arrangement of all equipment.

Socketless connections, for example, at an oven, are made under the countertop, near the wall, while sockets for a toaster, electric kettle, multicooker, and food processor are better placed above the work table.

Small household appliances are easier to unplug if the electrical installation device is at hand. Sockets installed near the sink must have degree of protection from IP44 or higher.

Review of common design mistakes

Defects in the design or planning of work entail installation errors, and this threatens disruptions in the functioning of the electrical network. The result may be the failure of expensive equipment, and even worse, an electrical injury to one of the residents.

What mistakes should you avoid:

• use low-quality products without labeling and certification;
• make one-to-one calculations - any technical products and materials must be purchased with a reserve;
• include in the project the installation of conventional sockets for connecting hobs, boilers, heat guns;
• in wooden houses plan the use of closed wiring - more complex and subject to the list of requirements of the PUE;
• design switching of low-voltage and high-power power wires in one distribution box;
• plan to connect wires using twists that are dangerous for further maintenance and operation; the best option is ready-made terminals;
• make circuits from aluminum and copper wires, and also use aluminum wiring.

Some errors relate to incorrect calculations. For example, grooves under the cable with a closed installation method should be laid to a depth of 2-2.5 cm, no less.

It is incorrect to place distribution boxes at the bottom or at human height. Their place is under the ceiling, 20 cm from a suspended structure or concrete ceiling slab

You cannot connect the grounding of sockets using a cable, or ground them on cast iron sewer or steel gas pipes.

If you do not know how to properly install electrical wiring in your home, contact the design organization. Specialists will visit the site and draw up a wiring diagram based on specific installation conditions.

Conclusions and useful video on the topic

Analysis of the floor plan:

Rules for drawing up electrical wiring diagrams:

Description of the device diagram on the distribution board:

Responsibility and risks for “independent activities” when drawing up a project fall on the shoulders of the home owner. If you do not have the appropriate education and experience, we recommend ordering documents from an organization that is engaged in professional development of power supply projects.

Do you have personal experience in designing and installing electrical wiring in a private home? Do you want to share your accumulated knowledge or ask questions on the topic? Please leave comments and participate in discussions - the feedback form is located below.