How to connect three phases to a private house?

Nowadays, a quality and well-thought-out power supply system is indispensable. If, when buying an apartment, this problem is not solved by the landlord, but by the construction company, then there is a choice for supplying electricity to a private house. Single-phase power has already been brought into the apartment, and even such voltage is quite enough there. However, in the private sector, a three-phase network can be quite relevant. In this article we will tell you which electrical network is better: three-phase or single-phase, as well as how to carry 380 volts to a private house by law and what documents are needed for this.

Advantages and disadvantages of a three-phase power supply system

It is no secret that the three-phase power supply of a private house becomes more and more relevant, and this is connected not only with the magnitude of the voltage. Let's look at all the benefits of 380 Volts and here is a list of them:

  1. Connecting the most common in everyday life and at work asynchronous electric motors squirrel cage rotor. When connected to a single-phase circuit, their power, torque, and efficiency are lost. After all, they were originally designed for three phases. The use of such electric machines in a private house may be needed when equipping a grinding, drilling or woodworking machine and other types of equipment. An owner who has the skills to work on such equipment will always find a use for him. A powerful pump is always useful at the cottage, so it’s not a problem to carry out 380 Volts.
  2. By connecting three phases, the owner of a private house receives, by and large, at once three independent single-phase networks, which he can dispose of at his discretion. To do this, in order to get a single-phase voltage of 220 volts, you need to connect one wire to the phase, and the other to zero. It will be called phase. The voltage between the two phases is 380 volts and is called linear. Read more about phase and line voltage in the article: https://my.electricianexp.com/en/linejnoe-i-faznoe-napryazhenie.html.
  3. In the event of a breakdown or emergency at a distribution substation, one or even two phases may burn out. At the same time, the owner of a private house with three phases will have at least lighting and a refrigerator. It should be remembered that for three-phase motors, two-phase operation will entail its inevitable failure.

Three phase metering board

Remember, and there are pitfalls. A three-phase network is needed if the power of a single-phase network is not enough. And even if single-phase is not enough, you do not need to rush to connect three phases, it is better to clarify about the possibility power limit increase for a single-phase network - this procedure is much simpler than matching and connecting the three phases.

Three phases must be connected in the event that it is necessary to power the three-phase electric motorsthat cannot work in single-phase mode, or in the case of the simultaneous use of a large number of electrical appliances, equipment, for example, if the house has a large farm, some small-scale production is established.

It should also be noted a few shortcomings of the three-phase power supply system. One of the minuses is the need uniform load distribution for each of the phases. The second drawback is the great difficulty in connecting, acquiring another shield, protective devices, etc. The third drawback is the great danger from the point of view of electric shock, since the house will not only have a single-phase voltage of 220 V, but also a linear voltage of 380 V

As you can see, the benefits of powering a consumer from a 380 Volt network are not always obvious. Now it’s worth figuring out what documents are needed to connect a three-phase network. We’ll talk about this now.

How to make a connection of three phases

Of course, before moving on to the technical side of the issue and directly connecting, you need to contact the company that is the electricity supplier in this particular region. To do this, the customer must clearly understand and agree on the following points:

  • Network power.
  • Type of meter and tariff. This can be a multi-tariff metering device or single-tariff.
  • The number of phases (in this case 3).
  • Wiring diagram.
  • Organization grounding, which is extremely necessary to protect people from electric current during breakdown or deterioration of insulation resistance.

Important! Independent connection to power grids is prohibited by law! The procedure for connecting and organizing energy supply should be carried out by highly qualified personnel. In order to connect a private house to a three-phase network, it must be completely de-energized, and it is also prohibited to do this without an energy service.

Suppliers adhere to clear requirements and rules. Therefore, if the distance from a private house to 380 Volt networks, most often passing through poles, will be more than 300 meters in the city (500 outside the city), then in order to conduct electricity, you will also have to pay support installation.

Electricity connection on the site

It is also important to note that often before connecting it is necessary to provide data on the status of home wiring. If the house has old wiring, then it is highly likely that representatives of the power supply network will not only not give permission to connect the three phases, but will also reduce to a minimum limit on a single-phase network for safety reasons, since the wiring can not withstand heavy loads.

The next key issue to connect the house to the 380 Volt network will be the power that the consumer will take from the network.

There are three degrees:

  • the first - no more than 16 kW;
  • the second - from 16 to 50 kW.
  • the third - from 50 to 160 kW.

Of course, it is better to organize power supply with a power margin, especially since the increase in the number of devices that operate on this type of energy is so far obvious. However, the cost of this system will be higher.

It is also important to note about the power limit - most often up to 15 kW is allocated to the average consumer. And in this case, it all depends on the state of the electrical networks, the power of the transformer in the transformer substation or in the transformer substation. If the capacity is small, then the supplying organization distributes approximately the power to the houses and it is impossible to connect above this capacity, especially three phases. In this case, to connect the three phases of the required power limit, you need a separate transformer - this is already a more complicated procedure, since you need to purchase transformer substations and connect to a high voltage network of 6 (10) kV. Therefore, the ordinary consumer has to be content with a certain power limit for a single-phase network.

The list of documents that should be for connecting 380 Volts (in addition to the application itself) includes:

  1. Identification.
  2. Tax-compliant taxpayer identification number.
  3. Title documents for residential or non-residential premises (in case of connecting a garage).
  4. Approved full residential plan (if available).

A copy is taken from these documents, which is submitted to the company by the electricity supplier. However, reconciliation with the originals is also required.

Some suppliers may also request additional documents, just in case, they also need to be taken with you:

  • Information about the power and a list of all available electrical equipment in a private house, in a garage or in the country. Depending on where you need to conduct three-phase electricity. If the connection is made to a site that does not have electrical equipment, then it will have to indicate its alleged types and power.
  • Information about their maximum power.
  • Estimated time to commission housing, if it is not a residential property.

Installation of multi-tariff meters is very beneficial, since if you do not use powerful devices during peak hours, you can save a lot. For example, at night the cost of electricity is several times cheaper than during the day.

The advantages of a dual tariff meter

The procedure for registering a multi-tariff meter:

  1. Preparation of an application requesting the installation of an electric meter.
  2. Obtaining the technical conditions for this meter, which must be purchased if the electricity supplying company does not have this equipment. Often they themselves provide not only connection services, but also sales of metering devices.
  3. Acquisition as well meter programming.
  4. Call a representative of the energy supply company to verify the correct connection of the meter, as well as its sealing.
  5. Making changes to the agreement or drawing up a new one, when organizing a new connection of three phases.
  6. Obtaining permission to connect 380 volts.

By the way, there is such an option as the conversion of single-phase voltage to three-phase. About, how to make 380 volt from 220 You can find out by clicking on the link.

The rated characteristics of circuit breakers must fully correspond to the load connected to them. There is no indicated power on the machines, only voltage and current for which it is designed are indicated on the case. About, how to choose a circuit breaker, we told in a separate article.

As for the technical part, namely the connection of three-phase voltage to a private house, it is better to entrust this matter to specialists, because in the absence of experience and skills, it will be almost impossible to independently carry out three phases.

Electric installation work

To make you understand how serious everything is, the following is an approximate scheme for connecting 380 volts in a private house, with wiring to automatic machines:

Three-phase power supply scheme

To familiarize yourself with the technology of the three phases, we recommend that you study the following block of articles:

Of course, in order to get a profitable, quite powerful and universal three-phase voltage into a private house, a summer cottage or a garage, you will have to spend some effort, time and money. Documents, coordination, connection, a more complex wiring diagram and therefore more expensive wiring, so think again carefully if you need three phases.

In the end, we recommend watching useful videos that explain the feasibility of connecting the three phases, as well as the nuances of preparing documents:

Now you know how to spend 380 Volts in a private house and what documents are needed for this. We hope our step-by-step instruction was useful for you and helped to independently connect the house to a three-phase network!

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3 comments

  • Boris

    The proposed scheme does not match the photo of the electrical panel. What is right? Differences. Connection of wire N. Wire N is connected through an automatic circuit breaker. Bus connection N and Pe. There is no circuit breaker after the counter in the diagram.

    To answer
  • Igor

    They told everyone besides the same thing anyway. Where to go where to look for public services how to write a statement how much it costs.

    To answer
  • Sergei

    I came to Energosbyt Plus, to find out what documents are needed to connect the 380 century. In addition to the basic documents, I was told to take the neighbors' consent to enter 380, since the house is two-apartment, and most importantly, you cannot make two drops to one semi-detached house from one support, I I want to spend three phases in my garage, and from a three-phase meter, connect my half of the house with one phase of 220 V. The essence of my message, why do I need the consent of the neighbors to connect 380 v.

    To answer

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