Replacing the wiring in the panel house with your own hands

New wiring in the panel house

How to change the wiring in the panel house? It is with such a question that many face during repairs. It would seem, what could be easier?

Just put a new one in place of the old one - that's all. But then the question arises: if we change the wiring, then it is worth adding a few sockets and switches. And since there will be new switching devices, then you should think about the new automatic devices. Once the load increases, then the cross section of the wires should be reviewed.

We will try to understand all these questions in our article.

Stage of planning and calculating the future home grid

The planning and calculation stage seems to be the most difficult for many. After all, if everything is correctly calculated and planned, then you will get a reliable and durable network, and the most time-consuming installation of the wiring will not be complicated by various unforeseen situations.

Select the number of points of power supply

Location of electrical points in the apartment

This is the most important and most crucial stage that will have to be performed before replacing the wiring in the panel house. After all, all our future calculations and the final cost of our power grid depend on it. Therefore, guided by logic, we must find a healthy compromise between the convenience of using electricity anywhere in the room and the final cost of an overly extensive network.

So:

• According to paragraph 12.27 of VSN59-88, in our apartment there should be at least 3 outlets in the kitchen and one outlet for every full 6m2 of living rooms. This is clearly an outdated standard and in modern realities we need significantly more outlets. Therefore, before we draw up a new plan for the location of outlets in each room.
• To draw up such a plan, we need to know the number of electrical appliances in each room. In addition, they should be divided into temporary and permanently connected to the network. This will significantly reduce the required number of outlets, as well as allow them to be placed economically and efficiently.
• For example, to connect video, audio and other household appliances that are permanently connected to the network, you should provide a separate outlet. But for connecting a hair dryer, iron or charging for mobile should provide a conveniently located one outlet. In general, we proceed from your habits and wishes.
• Do the same with switches. After all, zoning of lighting zones, the creation of additional lighting and other pleasant nuances that are able to create an atmosphere in your apartment are becoming increasingly popular. On this basis, the number of switches may also change, as well as their location. For each room it is worth making an approximate plan.

Calculation of the rated currents of each electric point

The next important step, which determines how to change the wiring in the panel house, is the calculation of the rated current of each outlet and switch. Based on these data, we will subsequently make further calculations, on which the final cost of our electrical network will largely depend.

So:

• First of all, you should pay attention to outlets. After all, the most energy-consuming electrical appliances are connected to this wiring device. The best option are sockets designed for a specific electrical appliance. In this case, we only need to look at the rated current in the passport of this device, and we will know the rated current of this outlet.
• If for some reason it is impossible to open a passport or the socket is intended for various electrical appliances, we should choose the most powerful of them. To determine the rated current of such devices, you can use our approximate load map of the devices or perform the calculation yourself.

The photo shows the approximate power of various electrical appliances.

• In order to perform the calculation, it is enough to remember Ohm's law, where the rated current is I = P / U, where P is the nominal (or at least approximate) power of our electrical appliances, and U is the voltage of our power grid, which is 220V for a single-phase network.

Note! In general, when calculating, we need to take into account a lot of parameters, or at least cosα, but we make a simplified calculation. Therefore, all unrecorded parameters will go as a certain safety margin for our power grid. And for low-capacity networks, which is the apartment grid, deviations will not be so fundamental.

• The calculation of the rated current of the switches is made according to the same formula. To obtain the rated power of the lighting network, it suffices to summarize the power of all the lamps. If the chandelier is on, then usually in its passport you can find the nominal power.

Note! On the basis of our calculations of the currents of each individual outlet or switch, we should also make the selection of the corresponding electrical installation devices. That is, if the rated current of the outlet you have turned out, for example, 7A, then you should choose an outlet with a rated current of 10A. The same applies to switches. In general, we have devoted more than one article to this issue, so we will not dwell on this in more detail.

Distribution of loads by groups

The distribution of loads by groups

Before you change the wiring in the panel house, you should determine the number of lighting groups. According to paragraph 7.2 of the BCH 59 - 88, apartments in residential buildings should be powered by at least two groups.

The nature of the load does not matter. That is, the lighting and outlet network can be combined in one group. Although quite often do separately outlet groups and lighting groups.

• The determining principle for us is clause 3.1.19 of the Electrical Code (PUE), which allows powering household appliances from automatic switches with a rated current of not more than 25A. On this basis, we also distribute our electrical network into groups.
• To do this, we summarize the rated current of all electrical points located in one or two rooms, until we get a value close to 25A. In this case, as we have said above, it is possible to divide the electric points by the nature of the loads. But most importantly, it is their compact arrangement, which will allow a few to save on the price of the wire.

Note! Paragraph 7.2 of the BCH 59 - 88 recommends combining the sockets installed in the hallway and in the kitchen. At the same time, the sockets installed in living rooms are recommended to be supplied with a separate group.

• As a result, depending on the number of electrical appliances, you should have from two to 5 groups.

Select wire size

At the next stage, our instruction advises to determine the cross-section of the wire (see Perform the calculation of the wire cross section for power ). This question scares many, but in fact there is nothing complicated here.

Knowing the wiring method, and for panel houses it is usually hidden wiring, as well as the load of each separate group, which we calculated above, the choice is made simply according to the tables.

• For copper conductors, the choice is made according to Table 1.3.4 of the EMP, and for aluminum conductors according to Table. 1.3.5 PUE. To make a choice, it is enough for us to know the number of wires, the method of installation and the rated current.

Summary table of wire cross section selection

• Whatever wire section you have for group lines, in any case it cannot be less than 1.5 mm2 of copper wire. This follows from table 7.1.1. PUE, in which the minimum values ​​of the cross-section of copper wire are indicated.
• In addition, when choosing, you must determine the number of wires to be laid in one section. If this number exceeds 4, then when selecting by tables, you must enter a correction factor of 0.68. If there are more than 7, then 0.63, well, and if the jointly laid wires are more than 10, then the coefficient will be 0.6 at all.
• In addition, the choice should take into account the ambient temperature, possible overload and some other nuances. But all this is designed for large-scale lighting networks. For an ordinary apartment, the first two points of this section will be enough.

Installation of wiring in the panel house

Having finished with the planning stage, you can proceed directly to the installation. In general, in panel houses, at the planning stage of slabs, special seams are provided for wiring. But often to get to them is almost impossible. Therefore, we consider the option of using these channels and without them.

Laying wiring in mounting seams

This is perhaps the most successful option, and for my practice I managed to use it only occasionally and only for the part of the network being mounted. As it is known, there are voids in the panels of houses, which according to the project are provided for laying wires, pipes and other engineering networks. We will try to use them.

Leaving wires from assembly seams

• In order for your wiring to get under the wall panels, you need first of all to determine where the old wiring penetrates it. If you already have bare walls, then at the locations of the electro points you should see the wires going into the walls. If these wires emerge from the wall somewhere between the seam of the panel and the ceiling, you have a chance to use it.
• If the old electrical wiring is found only at the switchboard, it means that it has several bends and, therefore, it is impossible to extend the new wire to the place and still not damage it.
• If we see the beginning and end of the wire, we can therefore try to lay our new wire to the channel. To do this, securely fasten the end of the old and new wires. As far as possible expand the hole in which the wire goes, and try to stretch the new one, pulling the other end of the old wire.
• When using this method, the new internal wiring in the wall panels gets through the old channels. It turns out not always. Sometimes the wire in the process of pulling is damaged so that it is no longer suitable for further use. Although sometimes this procedure is very simple and convenient. Then how lucky.

Wire laying by wall chroming

Wall chipping Perhaps the most time-consuming process during the replacement of electrical wiring. Of course, there are now strobe cutters that are able to make beautiful and deep strokes in just a few minutes. Moreover, do it without dust and dirt. But the price of this tool, to put it mildly, bites.

Wall chipping

• Usually you have to use a good old punch and centimeter by centimeter to bite into the wall. In order to simplify at least a little this task, you can use the grinder, but the amount of dust will increase significantly.
• In order to simplify the process of shaving, we recommend using seams between the plates. Usually they have a not so dense structure and give up quite easily even under a perforator.
• Quite often, even in prefabricated houses, old wiring is routed by the method of shaving. In order to maximally simplify your task, we advise you to make the most of these places for laying new wiring.
• To fix the wires in the grooves, you can use alabaster or special dowel-clamps. The latter method is more convenient, although it will require you to make holes in the wall for fixing such clamps.
• Of course, laying wire in a screed, under plinths and other methods is gaining popularity now, but it is almost impossible to describe all of them in one article. Moreover, most of them have already been analyzed in sufficient detail in previous articles on our site.

Conclusion

As you can see, wiring in a panel house from scratch is not such a difficult task. It is enough to approach this issue carefully and deliberately. And this concerns not only the planning and installation of the wiring. Connecting all electrical points will also not cause you any special problems, especially since the articles on our website will always help you to deal with all questions.