Electrical wiring project in a private house: how to choose

Designing electrical wiring in a private house is quite troublesome, but quite feasible even without special knowledge. It is enough to take a balanced approach to this issue. Well, our tips given in this article will allow you to step by step create your own electrical wiring project for any private house.

Any development of an electrical network project begins with determining the total power of the consumer, in this case our house, and its power circuit. And if the total power of the consumer in our case is determined by the energy supply company, which sets the consumption limit, then we have the right to design the scheme of the internal electrical network on our own.

So:

• The wiring device in a private house is as follows. On the outer wall of the house, the energy supply company installs an introductory machine and a meter. The connection of these electrical devices is also carried out by the power supply company.
• But after the meter, we already carry out the input to the house, the connection to the switchboard and the wiring around the house on our own. And here we have the right to choose a convenient power supply scheme for us.
• Usually the power supply scheme of the house is as follows. The cable or CIP wire from the meter is connected directly to the busbars of our switchboard. Separate power supply groups are powered from these buses. Each group has its own power circuit breaker installed on the phase conductor. The neutral and protective wire of each group should not have switching devices.

Note! The neutral wire of individual groups can have a switching device, only if connected through an RCD machine. The RCD machine can be installed both on a separate group and as an introductory for all groups. The issue of choosing the installation site of the RCD is not standardized by the rules of the PUE and remains a controversial issue. But based on operating experience and the personal opinion of the author of these lines, we advise you to install them separately for each group.

• Further, the wire or cable from each group machine is mounted to junction boxes. Each group can have from one to several junction boxes.
• From the junction boxes, the electrical wiring is distributed to the final consumers - sockets and switches.

Designing an electrical network at home

Based on the above general power supply scheme for the house, to design the electrical network, we first need to calculate the number of groups and distribute the loads among them. In order to do this, we need to decide on the method of wiring installation and calculate the possible load of our consumers.

Choice of wiring method

Let's start by choosing a method for installing an electrical network. The wiring of a private house can be done in an open and hidden way. And not only the number of groups, the cross-section of wires and the total cost of installation, but also the appearance of the whole house depends on the right choice.

So:

• First of all, we note that any type of wiring installation can be implemented in a house of any design and from any building materials. The only question is the cost of installation work. We will not give installation standards for different types of wiring in different conditions. You can find this information in other articles on our website. Let's just stick with the generally accepted rules.
• Open wiring has found wide application in houses made of combustible materials. First of all, it is wood, SIP panels and other types of combustible building materials. For such houses, the price of installing open wiring is often much lower. Hidden wiring will require considerable financial investments, and its installation is laborious.
• Hidden wiring is used mainly in the houses of their bricks, foam blocks and other non-combustible materials. After all, this type of wiring allows you to completely hide engineering networks, at the same time, in houses made of non-combustible materials, it does not impose special requirements.

Calculation of the total load at home

At the next design stage, you need to calculate the total load for the house and for individual electrical receivers. This is necessary for the subsequent formation of groups.

• To do this, we first need to determine the number of electrical outlets and their maximum power consumption. This often becomes the most serious problem for non-professionals, but de facto there is nothing difficult about it.
• Each socket or switch in the house is mounted for a specific electrical appliance or a group of electrical appliances. It is enough for us to choose the most powerful of them and continue to calculate for it.
• The power of the appliance can be viewed in the instrument's passport. It may also contain an instruction manual. If you do not have one or the other, then you can find out the approximate power in our table.

• But in most cases, the power of the devices is indicated in Watts, and we need to convert it to Amps. To do this, you can use Ohm's law -. In general, this is a simplified version of the formula, but for our purposes this is quite enough. Based on this formula, we get that an electrical appliance with a power of 1 kW for a 220V network consumes an electric current of about 4.5A.

Distribution of loads by groups

After we have calculated the total load for the house and for each individual electrical point, we can proceed to the direct creation of groups.

So:

• According to clause 9.6 of VSN 59 - 88, the rated power of circuit breakers for supplying group lines of sockets and the lighting network should not exceed 16A. Based on this point, we distribute our loads into separate groups.

Note! To power powerful electrical receivers such as an electric oven, it is allowed to install group machines with a rating of 25A.

• The distribution of the load into groups should be made based on their location and type of load. So quite often the group lines of the lighting network are separated from the power groups of the sockets. But this is not mandatory, and in some cases it is not advisable.

• It is also worth remembering that it is not easy to install the electrical wiring in a private house yourself. Therefore, you should not place different electrical receivers of the same group in different parts of the house. Usually it is 1 - 2 adjacent rooms.
• Another aspect worth paying attention to is clause 7.2 of VSN 59 - 88. It requires connecting sockets in the kitchen and living rooms to different groups. Quite often, a socket in the bathroom is also included in the kitchen outlet group.

Note! Sockets in the bathroom are allowed to be installed only if there is a group in which an RCD socket is installed. At the same time, according to the PUE, the rated leakage current for such a switching device is normalized by a leakage current of 30mA.

• As a result, we can get from 3 to 7 groups, depending on the total load. Some may have more than 10 groups. But here it all depends on the size of the house and the number of electrical appliances. But according to the technical specifications, the introductory machine that is installed on the house rarely exceeds 25A, sometimes 40A.
• This should be remembered when dividing the load into groups with your own hands. After all, the likelihood that all electrical appliances will work at the same time is quite low. Therefore, you should soberly approach this issue and perform the distribution more balanced, taking into account such a factor as the utilization rate.

Wiring selection

Before you conduct electrical wiring yourself in a private house, you should also worry about calculating its cross section. After all, its durability and fire safety depend on this factor. This issue is especially relevant for houses made of combustible materials.

• According to clause 7.1.34 of the PUE, since 2001, only copper cables and wires should be used in residential buildings. Prior to this, aluminum wires were allowed, which can often be found in old houses.
• As for the cross section of the wires, it should be selected based on the load on the group line. But in order not to do a lot of calculations and simplify the choice, we can proceed from the nominal parameters of group machines.
• In addition, when choosing the size of the wiring, the method of laying the wires should be considered. After all, heat transfer for wires laid in a hidden and open way is different. In this regard, although slightly, but depending on the load, their cross section differs.
• The choice is made according to Table 1.3.4 of the PUE. In addition to the loads and the laying method, it also takes into account such a parameter as the type of wire.

• But no matter how the wiring itself is chosen in a private house, it should be remembered that the cross section must not be less than that shown in Table. 7.1.1 PUE. For group lines, it must be at least 1.5 mm 2.

Conclusion

In our article, we have given the main stages of designing an electrical network in a private house. As you can see, there is nothing complicated in this, and the video on our website should make this task even easier. The main thing is to approach this issue carefully and carefully, and you will surely succeed.