1. What is the power supply network SNT?
2. When is a new project being developed?
3. Specific calculation of power consumption
4. What is included in the project SNT network?
5. What advantages does the customer get by ordering the development in Mega.ru?

Of all types of electrical design, the project of power supply for SNT can be called without exaggeration the most difficult from an organizational point of view. The construction of such settlements most often occurred spontaneously and rarely coordinated with the capabilities of a regional power supply network.

Given that in recent years, the popularity of suburban housing has increased dramatically, garden and garden communities are gradually turning into completely settled settlements, which almost always leads to a significant shortage of electricity.

One of the ways to overcome the difficulties in the modernization of the power supply network of the garden village is an advance and professional design of the power supply for SNT, performed by a licensed organization.

On the one hand, a well-executed project will allow you to calculate the exact estimate and determine the necessary funding levels. On the other hand, it will be possible to reasonably demand an increase in power limits in energy sales.

What is the power supply network SNT?

Recall that the SNT - gardening non-profit partnership - an association of owners of suburban areas, the purpose of which is to ensure the normal functioning of the village.

Obviously, without power supply, no “normal functioning” can be achieved; therefore, one of the main tasks faced by the SNT board is the creation and maintenance of the electricity network of the garden community.

Calculation of voltage drops

Considering that the majority of settlements of this type were originally created without plans for general development, the primary electrification of such facilities was carried out on the basis of minimum consumption norms. Even now in the suburbs you can find a sufficient number of dacha cooperatives, the total allocated power for which does not exceed 15 kW.

From a technical point of view, the power network of the dacha settlement before the modernization, as a rule, consists of the following elements:

• Low-power transformer (10 / 0.4 or 6 / 0.4);
• Outdated aerial transmission lines of electricity (as well as their complete absence near new sites);
• The inability to use basic household appliances and installation of electrical systems for autonomous water supply and heating.

After modernization, which usually occurs with the replacement of a substation with a more powerful and modern one, the network of energy supply to garden settlements in terms of power quality is comparable to urban areas.

In the light of all of the above, the reconstruction of the power supply schemes for holiday villages is almost always carried out with the aim of increasing the capacity, which, in turn, requires a complete reworking of the existing power grid project.

In addition to designing, the partnership board needs to find an answer to two main questions accompanying the creation of a new energy supply network in villages of any type:

• Who will pay for its maintenance?
• How to increase the power limit?

As practice shows, to answer them is so difficult that some stories on the renewal of the village electric networks last for more than a decade.

From the legislative point of view (FZ-217 of 07/29/17), the entire infrastructure of the village power grid is transferred to the partnership balance. That is, all participants of SNT should not only pay for the consumed electricity, but also regularly “throw off” on its maintenance (which is tens of thousands of rubles per year).

As for the increase in power, here it is necessary to find a balance between the 10 kW (per one plot) laid down by law and the capabilities of the local power supply network.

When is a new project being developed?

According to the requirements of PUE, any electrical installation, re-mounted or put into operation after modernization, can be connected to the power grid only after signing the certificate of admission to the connection.

What is meant by a clear sequence of actions:

• Development of electrical project;
• Matching;
• Installation;
• Laboratory measurements;
• The signing of the act of admission to connect;
• Technical connection.

Based on this, the design of electricians of the village is necessary both during electrification from scratch and during the reconstruction of the existing network.

Separately, we note that the need for modernization also arises after the emergence of new sections, for the electrification of which it is necessary to install additional supports in the power transmission line, which also requires updating the project.

Specific calculation of power consumption

The total power consumption of the power supply network is the main parameter on which almost everything depends on the developed (and in the current!) Electrical project. Including the size of the limit allocated for one connection.

New feed line

The method of its calculation should be known not only by the designer, but also by each participant in the garden partnership, since in 98 cases out of 100 this parameter is the cause of conflicts between the board and ordinary participants in the partnership.

The fact is that the actual power limit allocated to one site is determined not by a linear formula, through a simple division of the transformer power by the number of consumers, but by a much more complex algorithm.

In practice, the starting point for calculating the main parameters of the project is not the legally stipulated limit, which should be allocated for one country house (up to 15 kW), but the typical power of a transformer that meets the specifications formulated by the power supply company.

For example, suppose that the transformer power in the gearbox is 160 kVA, and the number of sections is -200.

First of all, the active component of the transformer rated power is calculated. 160 * 0.95 = 152 kW.

Further, it is necessary to take into account the technological losses on the delivery of electricity from the transformer to the end user. From a physical point of view, these are losses due to cable resistance and switching nodes, which depends on the state of the power grid. In the "good" network, such losses do not exceed 5%, in the "bad" they can reach 11%. Suppose that the network considered in this example is “average” and dissipates 7% of the transmitted energy.

We get the remaining active power of 152-7% = 143 kW.

Since in any village there are permanently working facilities of the general infrastructure, it is necessary to subtract from the resulting balance the cost of maintaining the performance of these facilities.

Autonomous water supply

Let us assume that such objects are street lighting and the operation of deep well pumps, the total capacity of which is 11 kW.

In total, 132 kW remains for distribution to final consumers from 160 kVA.

Please note that if you divide arithmetically 132 kW into 200 plots, you get only 0.66 kW per connection, which is clearly not enough even for the Soviet version of a country house.

Further calculation is performed on the assumption that all consumers rarely load the network at the same time, so the number of connections in formula 132/200 can be reduced by a certain factor, called the coefficient of simultaneous consumption.

For horticultural cooperatives, its value is assumed to be 0.14, after which the actual power available for one consumer is calculated.

132 / (200 * 0.14) = 4.7 kW.

It is noteworthy that when increasing the number of plots, the coefficient of simultaneous consumption decreases, which makes it possible to connect new consumers without installing additional transformers.

Separately, we emphasize that the above sample of calculations is valid only for those cases when electricity is not used for heating. More accurate guidelines for planning the distribution of power in power grids are provided in RD 34.20.185-94 (with additions), and SP 31-110-2003.

What is included in the project SNT network?

KTP installation diagram

Unlike other electrical projects, the working electrical project of the power supply network for the garden community is mainly focused on external communications, therefore, apart from electrical calculations, it should contain information for the installation of transformer substations and supports under the power transmission lines.

A typical package of project documentation consists of the following sections:

• Descriptive part (explanatory note);
• Plans for supply networks, developed on the basis of the cadastral explication of the village;
• Single-line VRU (input switchgear) and gearbox (integrated substation);
• Scheme-calculation of voltage drops for all sections of the supply line;
• Scheme-calculation for short circuit currents;
• Calculation of losses in the transmission line and in the transformer KP;
• Power equipment layout;
• Installation scheme and description of the grounding complex;
• Lightning protection scheme (depends on the climatic characteristics of the region);
• Schematic diagram of the connection of metering devices (with an indication of the characteristics of measuring transformers);
• Specification;
• Economic calculation (or estimate).

When developing, the limitations specified in SNiP 3.05.06-85 "Electrical devices" and SNiP 12-01-2004 "Organization of construction" should be taken into account.

Single-line scheme of VRU and KTP of the village

What advantages does the customer get by ordering the development in Mega.ru?

The economic and organizational need to study all the elements of the electricity network of the dacha settlement has already been mentioned above. But the review will be incomplete, if not to mention the additional benefits that a professionally developed project gives:

• Reducing losses in the power supply network;
• Higher reliability of internal transmission lines for transmission of electricity, achieved through the use of self-supporting CIP wire;
• The almost complete elimination of opportunities for the selection of electricity to bypass the metering devices;
• Significant reduction of the risk of emergency situations due to the use of the most modern automatic protection systems (as a result - reduction of the risk of financial losses);
• Exact division of areas of responsibility;
• The possibility of further modernization without major capital expenditures (including the connection of new consumers).

The Mega.ru company accepts orders for the development of power supply systems of any category of complexity, including projects for the power supply of garden and dacha settlements located in the Moscow region and adjacent regions. You can clarify the details of cooperation and apply for departure of specialists for a preliminary survey of the object, using the feedback form or by calling the telephone numbers listed in "Contacts" .