How to replace the electrical wiring in the apartment?
In most cases, when renovating an apartment, a complete replacement of the electrical wiring is required, especially if the house was built in the 60s and 70s of the XX century. At that time, the wiring load was determined at the rate of up to 1 kW in cities with a population of up to one million and up to 1.5 kW in cities with a population of more than a million. However, the power of modern household appliances ( water heater , microwave oven , electric stove and / or oven, warm floor, electric fireplace, etc.) sometimes exceeds the threshold of 10 kW, which requires replacing outdated wiring, especially since its warranty period does not exceed 20 years.
According to the old standard, the apartments used an aluminum cable.with single insulation - APPV. It is cheaper than copper, but it conducts electricity worse and easily oxidizes when the insulation cracks. It is now preferable to use copper cable, which is more durable and better withstand modern loads. The most common use of wires of the VVG and VVG NG brands (non-combustible cable).
The main stages of installing a new electrical wiring
1. We draw up a diagram or drawing of an apartment, on which we put all the sockets, switches and illuminators. To facilitate the work, we divide everything into groups according to the type of consumption - an electric stove, sockets, a bathroom, lighting... We lay a separate cable for each group from the main switchboard. This not only saves you money on the purchase of a thicker cable, but it also eliminates the need to make additional connections in the junction boxes, thereby increasing the reliability of the wiring. It is also undesirable to connect all the wiring to one group. For example, it is better to connect the bathroom with a separate line, equipping it with an RCD or a difavtomat.
2. We buy the calculated number of machines and cable. If the wires are partially replaced, make sure that the connections are of the same type. Since copper and aluminum cable is not recommended to be connected together due to the rapid oxidation that destroys the contacts.
Types of wires used for power supply:
- for lighting, a two-core VVG cable with a cross section of at least 1.5 square meters is used. mm;
- for electric stoves, a three-core wire with a cross section of at least 4 square meters is used. mm;
- a three-core cable with a cross section of at least 2.5 square meters is suitable for sockets. mm.
3. We remove the old wiring (in whole or in part). To do this, we de-energize the entire apartment by turning off the packet switch. After that, we begin to dismantle the old wires and devices. We open the cover of the junction box (usually they are located under the ceiling), cut and insulate the lead-in cable, and then remove all the old wires. If any wire cannot be removed, it is cut and insulated.
4. We punch the grooves for the new wiring using a wall chaser or a grinder with a perforator. Remember, grooves are punched only in the vertical or horizontal direction. In no case should the channels be laid diagonally so that they do not subsequently fall into the laid wiring with a nail or drill. The depth of the strobes depends on the thickness and number of wires. If the wire is not one, but several, the channel is expanded so that a distance of at least 3 mm is maintained between them.
With the help of crowns, holes are punched for sockets, switches and junction boxes. At the same time, the edges of the recess do not have to be made even at all, all defects can be easily hidden with the help of a plaster mixture. The installation height of sockets and switches is set according to personal taste (usually the switch is installed at a height of about one meter from the floor, and the sockets at a height of about 30 cm).
5. We lay the wires and fix them with dowels-clamps. The distance between the dowels should not exceed 30 cm.
6. Using a tester, we check all the wiring for a short circuit, then connect the sockets and lamps. After that, we connect the voltage and once again check the lighting devices and sockets with a tester or phase indicator.
7. We close the laid channels with plaster mortar.
Upon completion of the finishing, the new electrical wiring in your apartment is ready for use.