Rules for wiring - how to make installation in compliance with the rules and regulations

After people began to use the energy of electricity to perform useful work, they immediately ran into questions of getting electrical injuries from burns that occur when exposed to electric current.

For example, back in 1753, on July 26, professor of the St. Petersburg Academy of Sciences Georg Wilhelm Richter, while conducting experiments with atmospheric electricity, died from contact with ball lightning. After this incident, such studies were immediately suspended, and the causes of what happened began to be studied.

Almost all the leaders did this after each accident to study the causes of its occurrence. As a result of the collection of accident statistics and their detailed analysis, recommendations were developed on the safe behavior of people in order to maintain their health and ensure the normal operation of the equipment.

Over time, they were legally formalized with the requirements of norms and rules that had to be studied and observed by all employees when handling any electrical devices.

The wiring rules are divided into two main sections:

1. organizational measures created in order to exclude access to work with electricity to untrained persons;

2. technical measures that determine a strict sequence of actions for already trained employees, excluding the possibility of electric injuries and cases of malfunctioning of existing electrical equipment.

Purely theoretically, it can be argued that anyone can independently carry out the installation of electrical wiring and perform it with their own hands without assistance. This is nothing complicated if you go through the preparatory stage - theoretically study the current rules with safety standards and gain practical skills for their implementation for the strict implementation of organizational and technical measures.

Depending on the preliminary preparation and practical necessity, the time for mastering the rules for safe installation can be several years, provided for by the training program in specialized technical institutions, or require a significantly shorter period.

The main directions of development of the rules for wiring

The basic principles of electrical safety standards include:

• supply voltage only to the electrical circuit for load consumption prepared for this;

• Targeted passage of current exclusively along the specified driving routes, ensuring minimal energy loss to overcome electrical resistance and heat equipment;

• maintaining the dielectric layer of the wiring in good condition and eliminating the formation of extraneous leakage currents through the occurring points of insulation failure;

• ensuring long-term operation of electrical equipment at nominal parameters of the power circuit;

• the most rapid release of voltage from the existing electrical installation with automatic protections in the event of emergency damage for any reason.

To implement these rules, various methods of wiring are used:

1. open gasket for building structures;

2. premises inside the structures of walls, ceiling, floor;

3. combined method.

For all three methods, there are general requirements of the rules and regulations for safe installation and specific, specific features of the methods for wiring are developed.

A number of important things to consider when installing an electric wire in an apartment or part of a house were previously considered here:

How to make the power supply of the apartment reliable

What technical characteristics of wires and cables is important to consider for reliable operation of wiring

How to correctly divide the wiring into groups 

How to do the installation of hidden wiring

General safety requirements

Among the large number of rules, four actions stand out, which for some reason are often violated inside residential buildings and therefore require close attention:

1. access to switching devices;

2. places for safe placement of circuit breakers;

3. methods for installing outlets;

4. methods of laying cables and wires.

Access to wiring points

The quality of wires and cable products, as well as sockets, switches and junction boxes that are in operation, is subject to periodic technical inspection and control. This requirement cannot be violated for the simple reason that any electrical equipment is created to work under optimal conditions, which the manufacturer specifically indicates in the accompanying documentation.

In practice, emergencies occur occasionally associated with overvoltages of the electrical circuit and the flow of short circuit currents through it. This dictates the need to periodically visually monitor all switching points, to have convenient access to the created electrical contacts in the places of their connection.

However, many apartment owners, in pursuit of the beauty of the room, hide all junction boxes with the connection points of wires and cables inside the walls, cover them with a layer of plaster, and additionally cover with a layer of wallpaper on top.

This action not only excludes the possibility of periodic inspection of electrical wiring, but also complicates the search for malfunctions, requires the destruction of the decorative coating, and sometimes the cost of finding the location of branch boxes.

Switch Placements

The lighting scheme of each room provides for the use of an individual switch for each lamp, which is connected by cable through a junction box.

It is customary to mount all the switches of the apartment uniformly, based on the conditions of comfortable control. It is advisable to place them at the entrance to the room at the door in order to conveniently use the light without creating unnecessary movements.

The old typical mounting height of switching devices 1.5 meters from the floor can be inconvenient for young children. This requirement is especially relevant for a children's room and toilet. Installation of switches at the level of the lowered hand of an adult in these rooms is convenient for residents of all ages.

Outlet locations

Modern standards do not strictly limit their height and placement at the level of 0.5 ÷ 0.8 meters from the floor, as was often practiced earlier.

The main location conditions are ease of use and ensuring electrical safety. Installing outlets at a height of 20 ÷ 30 cm from the flooring makes them less visible in the interior, allows you to hide various elements of furniture, provide good access for repair and inspection.

Since there are a lot of household appliances inside modern rooms that require electrical power, it makes sense to use outlet blocks or groups of them. They exclude heap of tees and extension cords. But in this case, it is important to take into account the current load on each socket mechanism and power cable, maintaining the power balance of all connected devices.

For portable consumers, such as a vacuum cleaner or power tool, an additional number of outlets in each room should be provided.The rapid development of household appliances clearly proves that after some time the room begins to run out of free sockets and apartment owners begin to use extension cords.

When placing outlets on building partitions between rooms, often install outlet groups located on opposite sides of the same wall. This saves money and installation time by supplying one cable from the junction box with a series connection of it to the power contacts by a cable.

Features of the placement, installation and connection of sockets were previously considered in these articles:

Installation height of switches and sockets from the floor

Installation of sockets and switches on various surfaces

Installing the box under a switch or outlet

How to install and connect the socket-switch block in one corps

How to install and connect a telephone jack

Features of installing electrical equipment in the kitchen

It is important to immediately accurately plan the number of outlets in the kitchen, where many electrical assistants work.

It is justifiable to make them several blocks and groups, highlighting in a separate circuit power circuits for an electric stove, dishwasher or washing machine.

The rules for installing electrical wiring and sockets in the bathroom, kitchen and toilet require increased attention. These are rooms of high humidity. For them, standards and rules have been developed for the four safety zones for using electrical appliances.

Features of the installation of electrical bathroom

According to the safety conditions for using electricity, the bathroom is divided into four spatial zones.

In zones No. 0 and No. 1 they do not use electrical appliances, but do not install sockets and switches. In zone No. 3, it is permissible to install a stationary outlet with a high class IP housing protection and a lifting cover that prevents splashes and drops of water from entering the outlet when the plug is removed from it.

Given the need to remove humid air, it is permissible to use a forced ventilation system. But its electric motor should be placed at least 2.65 meters from the floor level of the bathroom, and only remote buttons should be used to control its operation. They are placed no lower than 2.25 m and switched by twitching over the hanging cord.

Hermetic lights placed on the ceiling, and switches - at the entrance to the room from the outside.

Inside the bathrooms, cases of the use of electrical appliances should be excluded, and if necessary, their frequent use, the sockets are powered through isolation transformers.

Ways to lay cables and wires

Among the electricians, there have long been certain traditions of installing wires and cables. They are especially relevant in hidden wiring because in the process of its operation they make it possible to foresee the passage points of electric highways, avoiding their damage during wall repairs, drilling holes for hanging paintings, shelves, furniture.

Routes of cables and wires are not laid along the shortest path, but only strictly in vertical or horizontal directions. Wherein:

• horizontal tracks are removed 5–10 cm from the surface of the cornices, beams and 15–20 cm from the baseboard or ceiling;

• vertical routes carry from the corners of walls or slopes of doors and windows no closer than 10 cm;

• if there is a possibility of contact of wires and cables with metal building structures, then they should be avoided;

• when the pipelines of hot water supply or heating are close, it is necessary to apply thermal protection of cables and wires, use a thermal protective coating;

• it is necessary to ensure the removal of electric lines from gas and other combustible substances by at least 40 cm;

• when there is a need for parallel laying of several cables, they are mounted not in a continuous stream, but at a distance of 3 mm;

• the conductors at the ground wires are used only intact without additional connectors. PE conductors are laid with a separate bus from the appliance to the apartment panel, and it is connected to sockets by a branch or through the PE bus.

Features of installing electrical wiring for different types of wiring

The placement of wires and cables according to different connection and location schemes on building structures is carried out according to general rules, taking into account specific developments for each method.

Layouts of wires and cables

Connecting consumers of electric energy in an apartment can be carried out in one of the following ways:

1. a star - radially located highways emanating directly from the apartment panel without using junction boxes;

2. dividing consumers into groups according to the principles of operation (lighting, outlets) and connection via junction boxes;

3. group connection on the principle of a serial loop;

4. combined method.

Star mode

The smallest number of places for connecting the ends of the cable cores is created. Due to this, increased reliability of the circuit is achieved. But it requires the greatest consumption of cable and material resources.

Connection via distribution boxes

By laying common lines between groups of junction boxes, cable consumption is significantly reduced, and its savings are created. However, the number of connection points of the wires increases significantly.

 

Loop method

The division of sockets into groups and the serial connection of nearby units allows you to further save cable. This method requires constant consideration of the load on the outlet groups. There is a high probability of their operation in overload and overheat mode.

Ways of installing electrical wiring on the building structures of the apartment

The most typical cases of laying wires and cables is their placement by:

• the ceiling;

• the walls;

• gender

• combined method.

Ceiling wiring

Cable channels come out of housing shield on planned highways and diverge on the premises. Wall outlets, switches and fixtures create downhills on the walls.

Installation of electrical wiring on the walls

Cable channels are arranged according to the wall covering structures, and for luminaires located on the ceiling they are led in separate lines.

Floor wiring

The wiring is located under the floor, and to the sockets and switches is led along the walls. The minimum number of highways in the walls eliminates their damage when drilling holes for hanging furniture elements and other similar works.

In practice, you can often find a combination of two, or even all three of these methods.

Features of an open method for wiring

The classic placement option is the method of mounting on rollers, which was widely used in the middle of the last century, and to this day has come in the form of a decorative technique, which has received the popular name Retro wiring.

The design of its special insulation layer is made with enhanced properties of electric strength and high resistance to ultraviolet rays. Due to the air indentation of the wires from the wall surface, a fire gap is ensured. It allows the use of open-circuit wiring, even on flammable wooden building structures.

The second popular method of open wiring is its implementation with a flat or round cable with metal strips fixed to the ceiling and walls, as shown in the photograph.

However, modern regulations permit such installation on the surfaces of only non-combustible materials.Direct contact of the cable with the wooden ceiling is prohibited: a fire may occur when the wires are shorted. Such fastening is permissible only on the walls of brick, stone, concrete.

Features of the closed method of wiring

Wires and cables can be located inside building structures, walls, floors and ceilings. At the same time they are stacked:

1. providing easy replacement in case of damage by pulling out of pipes or cavities;

2. stationary, without the possibility of withdrawal due to coating with plaster mortars and strong adhesion to them.

To create a closed wiring, a cavity is required in the walls and building elements. They are created during construction, drilled or drilled during repair. It should be borne in mind that such actions weaken the mechanical characteristics of load-bearing structures and may lead to their collapse.

Great technical difficulties are caused by the correct installation of closed electrical wiring inside buildings of combustible materials:

• wooden logs;

• timber;

• SIP panels.

For them, it is necessary to use brands of cables with insulation not only not supporting the combustion process, but also resistant to fire. Current standards and regulations require them to be placed inside sealed metal volumes formed by pipes or special casings.

This is explained by the fact that in the event of a short circuit, the case of such protection will not allow oxygen from atmospheric air to penetrate to the short-circuit point and maintain the burning of the electric arc. As a result, the fire will not receive support, the development of fire will be prevented.

Now this is the only correct way for the closed installation of electrical wiring in buildings made of combustible materials, but it is often neglected due to the complexity of technical implementation.

When choosing any method of wiring installation, it is necessary to take into account the possibility of a sudden occurrence of an emergency and provide measures for its rapid termination. This function is assigned to protective automatic devices that exist in the sale of a large assortment and perform various tasks.

Minimum protections are provided by circuit breakers and residual current circuit breakers in the complex. Their use in electrical wiring is a necessary and mandatory rule. About what you must pay attention to when choosing circuit breakers is described here: Criteria for choosing circuit breakers