The power supply scheme of a private house is a lot of ordered cables, wires, protective devices. The correct selection of parameters, characteristics of circuit elements guarantees the safety and comfort of property owners.
If the circuit is made up correctly, taking into account the requirements of the PUE and other regulatory documents, there is nothing to fear - the rooms will always have light, heat, and electrical appliances will not break due to power surges or short circuits in the network. Therefore, the design of electricians should be given special attention.
We offer to understand all the intricacies of this process. The article outlines the general requirements for the design of the power grid, provides practical advice on choosing wires, and also describes in detail typical wiring diagrams for electricians.
In addition, we have prepared a review of common mistakes, the account of which will help to avoid shortcomings in the design and installation of power supply networks.
General rules for the design of the power grid
When there were few electrical appliances, and several light bulbs for 40-60 W were enough for lighting, a primitive scheme was drawn up for the device of the power supply system, including several switches and sockets.
Now, with the advent of a large number of volatile household appliances, the circuit is necessarily differentiated into group lines protected by circuit breakers and other devices.
Up to a dozen devices can be connected in only one kitchen, 2-3 of which are powerful units that require dedicated power lines with an enlarged cable and separate outlets
If you consider all the nuances of the location of the wiring in a private house, taking into account the use of copper wire, it will last at least 20 years. Typically, the scheme is made together with the design of a new house or before a major renovation.
You should start by indicating the installation locations of elements such as:
- sockets;
- circuit breakers;
- junction boxes;
- lighting devices;
- powerful household appliances;
- electrical panel.
At the same stage, you should decide on the method of laying cables - open or closed. In houses with plastered walls, the closed method is usually used, with wooden - the open method.
Whichever scheme you use, there are a number of rules that cannot be retreated from. They are spelled out in regulatory documents, and their effectiveness has been proven for decades.
Here are a few important axioms of wiring, which will be required for drawing up a diagram:
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Electric wires, cables are laid horizontally and vertically. This norm reflects decades of operating experience in circuits.
When laying the wire, you can not turn it at an acute or obtuse angle, any rotation of the line should be 90 °. From the junction boxes and shields, the wires also extend at a right angle, the diagonal arrangement to reduce the distance and save material is prohibited
Do not place wires in close proximity to window and doorways, niches and portals. The minimum distance from the shtrob and cables laid in an open way is 15 cm. Accordingly, sockets and switches should also be at a distance of at least 15-20 cm
The optimal distance from the outlet block to the “clean floor” is 30-40 cm. The exception is power outlets installed in the working area in the kitchen, as well as in the bathroom, for a hairdryer or razor. They are mounted above a table or sink - for ease of use
The installation of sockets for computer equipment and TVs needs to be thought out in advance, determining their location. To save space, we recommend using modern modular units with network, television connectors and outlet groups
For powerful household devices - electric stoves, air conditioners, washing machines, others - provide separate lines protected by circuit breakers, other devices
The distribution switchboard with protective devices is installed at a height convenient for maintenance - approximately 150-170 cm from the floor. This height is an additional insurance against penetration into the shield of young children
When installing wiring in the kitchen, it is necessary to take into account the location of the gas pipe, which usually runs along the outer wall. According to the safety rules and installation of electrical installations, the minimum distance from a power line or outlet to a gas pipe is 20 cm
Wires are parallel or perpendicular to the floor / ceiling
The angle of rotation of the wires is strictly straight
Distance from power line to doors and windows
Remoteness of the outlet block from the floor
Outlet blocks for office equipment and video equipment
Individual power supply for powerful household consumers
Switchboard installation height
The location of the power lines relative to the gas pipe
In addition to the rules, personal comfort should be considered. For example, a double bed usually has two outlets installed - one on each side.
Switches are placed at a height of 80-90 cm from the floor. In large halls, corridors, rooms set passage switches.
To save energy on the stairs leading to the second floor or to the attic, LED lamps with motion sensors are installed, which are turned 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.
Guidelines for choosing wires
In houses made of bricks, aerated concrete blocks, cinder blocks, interior decoration of the walls is necessary, which means that they use the hidden method for laying wires.
To provide additional protection, and in case of repair, quickly replace the cable, it is placed in a corrugated sleeve of non-combustible polymer.
In houses made of timber or logs, to preserve the retro style, they use the open method of laying wires, acquiring decorative products - twisted wiring, rollers, stylized switches and sockets
In order to correctly select the wire cross-section, specialists make calculations related to the determination of the load.
However, relying on standard schemes and many years of experience, qualified electricians adhere to the following parameters:
- lighting circuits - 3 * 1.5 mm² or 3 * 2 mm²;
- outlet groups - 3 * 2.5 mm²;
- electric stove / oven - 3 * 4 mm²;
- air conditioning - 3 * 2.5 mm², for appliances 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 a three-core copper: VVGng, ShVVPng. It is impossible to use wires with a cross section less than the specified, since they will not correspond to the load and will begin to melt, creating a dangerous situation.
Analysis of wiring diagrams
Consider a few typical schemes that are used in construction or overhaul. All options are combined by the presence of a protective group: by dividing the electrical wiring into circuits, each of which is connected to a separate machine.
Option # 1 - a general scheme-plan for the whole house
This is not a wiring diagram, but a listing of all the electrical devices that are planned to be located in the house. Using it, you can calculate how many machines and RCDs are needed, and calculate the total number of power lines leading to the shield.
Here you must specify the type of mains in order to choose the right cable. For a 3-phase network, a 5-wire cable is taken, for a 1-phase network, a 3-wire cable.
For part of the devices is responsible for the organization that supplies electricity to the house. This is an electric meter and input protection device, which are usually installed on the outer wall of the house or on the pole leading the cable (+)
The switchboard is located in a separate room inside the house, in the corridor, in a nearby garage. They also install voltage stabilizers and a backup generator, which supplies the house with electricity during periods of disconnection of the centralized line.
For the convenience of servicing a two- or three-story mansion, an electrical panel is also mounted on each floor. All switchboards are connected to the input cable - a copper wire with a cross section of 15-35 mm².
It’s not worth saving on protection devices: it is recommended to install an RCD on each outlet circuit, automatic devices on the light lines for each room, as well as for air conditioners, a heating boiler, a “warm floor” system, etc.
If it is planned to arrange several lamps and sockets in a separate room, then at the entrance you need to mount a junction box. It connects the input cable to the lighting line and the outlet group.
Option # 2 - sample wiring diagram
To draw a wiring diagram, you need to take a house plan and mark on it the installation location of electrical devices.
This document becomes the basis for making an estimate - it is easy to count on it not only the number of switches, outlets 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 in the electric lines leading from the electrical panel to the rooms, the contours are indicated in different colors
Be sure to indicate the point of entry of the power line into the house and the place of installation of the electrical panel. Then, on separate lines, distribution boxes, electrical installations, lighting devices should be noted.
High power devices must also be labeled, as they are powered by individual lines.
If farm buildings are connected to the building - a bathhouse, a garage, a workshop - this should also be reflected in the diagram, as it is part of the electrical wiring in a particular private house.
For hand-drawn schemes, there are no special symbols, the main thing is that the owner of the house and the installers understand what is behind each symbol. However, it is better to use the generally accepted designations of electrical circuits in order to subsequently understand the project yourself.
Option # 3 - a technical solution for a small house
All plans and schemes are similar, since they are built on the same principle, however, they can differ in the number of installed outlets and light circuits, and therefore, in the number of protective devices connected to them.
A sample scheme for a one-story house, inside of which there are 3 rooms, a corridor, a kitchen, a bathroom. Power lines are assembled so that one of them combines a corridor and a room, the second - 2 rooms
An input circuit breaker is installed in front of the network, which, if necessary, can turn off the entire house and turn off the electricity meter. Then follows a counter, and after it - protective groups.
For powerful units, such as a heating boiler or a washing machine, machines are installed at 25-40 A. Wire cross section should also be increased to 3.5-5 mm².
With this scheme, you can not calculate the footage of the wires, but the number of sockets, distribution boxes, switches, RCDs, automatic machines is easy to calculate.
Option # 4 - wiring diagram for the basement / garage
Often the basement of a private house becomes a utility room where they install a washing machine and equip a dryer, 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 electrical wiring with an electricity meter. If the garage is in the basement or in the annex, a separate meter is not needed.
If you do not take the meter into account, the input circuit breakers, grounding bus, 20 A RCD, three circuit breakers will remain on the switchboard: on the lighting line, for outlets and for the compressor. Additional powerful equipment also needs automatic protection.
Option # 5 - Kitchen Wiring Principles
The electric circuit for a kitchen in a private house is practically no different from a similar circuit for a city apartment.
Its feature 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 outlet blocks in such a way that they are close to the devices and at the same time in free access, for possible repair or switching devices (+)
When drawing up a vertically oriented diagram, it is necessary to display a furniture set on paper with the arrangement of all the equipment.
Mesh-free connections, for example, near the oven, are made under the countertop, near the wall, while sockets for the toaster, electric kettle, multicooker, combine harvester are best placed above the desktop.
Small appliances are easier to unplug if the wiring device is at hand. Sockets mounted near the sink must have a degree of protection against IP44 or higher.
Overview of Common Design Errors
Deficiencies in the scheme or work planning entail installation errors, and this threatens violations in the functioning of the power supply network. The result may be the failure of expensive equipment, and even worse - an electrical injury to one of the tenants.
What mistakes should be avoided:
- use low-quality products without labeling and certification;
- make one-to-one settlements - any technical products and materials must be purchased with a margin;
- lay in the project the installation of conventional outlets for connecting cooking surfaces, boilers, heat guns;
- in wooden houses to plan the use of closed wiring - a more complex and obeying the list of requirements for PUE;
- to design switching in one junction box of low-voltage and powerful power wires;
- to plan the connection of wires dangerous for further maintenance and operation of twists; the best option is ready-made terminals;
- make chains of aluminum and copper wires, and also use aluminum wiring.
Some errors relate to incorrect calculations. For example, the cable gates with a closed installation method must be laid to a depth of 2-2.5 cm, not less.
It is not correct to place the junction boxes below or at the level of human growth. Their place is under the ceiling, 20 cm from the suspended structure or concrete ceiling slab.
Do not connect the grounding of outlets using a loop, grounding on cast-iron sewer or steel gas pipes.
If you do not know how to properly conduct the electrical wiring in the house, contact the design organization. Specialists will leave the place and draw up a wiring diagram, based on the specific installation conditions.
Analysis of the floor scheme:
Rules for drawing up wiring diagrams:
Description of the device diagram on the distribution board:
Responsibility and risks for "initiative" in the preparation of the project rest with the owner of the house. If you do not have the appropriate education and experience, we recommend that you order documents from an organization that is engaged in the professional development of power supply projects.
Do you have personal experience in designing and wiring electricians in a private house? Want to share your knowledge or ask questions about the topic? Please leave comments and participate in discussions - the feedback form is located below.