What is the difference between a temporary power supply of a construction site and a permanent one. Power supply of the construction site Sample estimate for temporary power supply

Starting the construction of a house, you definitely need to worry about the electrification of the construction site, since there is practically nothing to do at a modern construction site without the help of power tools. Concrete mixers, jackhammers, perforators, cutting machines, drills, welding machines are powered by electricity and greatly facilitate and speed up the construction stages, so temporary power supply of the construction site is the first stage of any construction.

Electrical network requirements

First of all, we provide the requirements for temporary power supply of the site where construction work is carried out:

1. Reliability. Uninterrupted power supply during the construction period.
2. Quality. Frequency and voltage must guarantee the operation of electrical devices.
3. Security. Maximum protection for personnel and operators on the construction site.

To do this, it is necessary to document the organizational issues associated with connecting to existing highways of sufficient capacity.

Organizational events

Depending on the location of the site on which the construction takes place, the choice of a method for supplying temporary power is carried out. The following points influence the choice of cable laying type:

• Distance from power lines.
• Type of object: residential building, warehouse or production workshop.
• Estimated power consumption.
• Choice of network: single-phase or three-phase.
• Condition of the nearest overhead power line.

Based on these options, the best way to install temporary power supply at the construction site is selected. This may be a connection to existing networks or the installation of an autonomous power generator. When connecting to the power grid, it is better to individually find out in the power grid and in the energy sales organization the calculation procedure and other conditions.

Features of connection to existing electrical networks

The first situation that we will consider is that construction is carried out in the immediate vicinity of one's own housing. The method of electrification from an already registered input is considered less expensive and more preferable. For the duration of the construction work, electricity is consumed, which is already present at the facility and payment for it occurs in accordance with the previously concluded contract. This option is suitable for temporary power supply of a private house.

After the construction of a new facility and, possibly, the dismantling of old buildings, it will be necessary to re-register the contract with the supply organization.

For this you need:

1. Specify the estimated power consumption.
2. Have an organization and a connection point for input.
3. Order project documentation.
4. Coordinate the project with the state technical supervision.
5. Carry out electrical work.
6. Call an electrical laboratory to evaluate and draw up a test report.
7. Conclude an agreement with the energy sales company, put the facility into operation.

All documents are provided in the photo:

Please note that in order to make temporary electrical wiring, you will also need to issue this package of documents.

In cases where the construction site is located far from power lines, it will be necessary to build a new overhead line (or lay a cable). To do this, you need to contact the power grid organization and write an application for a technological connection, after which you should be given a technical specification. After completing the documents, you must fulfill the conditions of the technical specifications and re-apply to the network organization to connect the shield to and seal the metering devices. For more information about connecting, see the video:

Input at the facility should be done as for permanent operation. To do this, you need to install an external vandal-proof shield with an IP54 protection class. The box is set in such dimensions that it is possible to install a meter and protection devices, sockets and grounding buses. You also need to provide a place for backup power supply.

During construction within a non-profit partnership, the cost of services for collective connections is much cheaper than dacha, horticultural and garage cooperatives. They have a transformer substation to which it is possible to connect. Many teams have already settled down and formed. Repair and modernization of equipment was carried out at their expense, transformers, laying of overhead lines. Newly appeared developers can be presented with monetary compensation from the work already carried out and the modernization of some equipment.

Another situation that I would like to consider is the temporary power supply of a private house from neighbors. If, due to reasons beyond your control, electrification is being debugged, and the deadlines are running out, then it is worth negotiating with the neighbors. If such a kind person was found, through an additional metering device, the power supply is connected for the period of repair and construction. The amount of output power is agreed in advance (control by metering device) and the installation of a protective restrictive device. In this way, it is easiest to make temporary wiring to the site.

Separately, it is necessary to consider such a method of supplying electricity as. From a technical point of view, generator sets provide high-quality electricity. Builders use them at their own discretion and do not depend on anyone. The disadvantage is the high cost of the generated electricity. This type of supply is mainly resorted to at the beginning of construction, when there was a hitch with temporary supply at the stage of paperwork.

Technical measures

After all organizational issues have been resolved and a temporary power supply scheme has been selected at the construction site, a place is determined for installing the input shield on a rack or support. An additional support is also installed if the site is more than 25 meters away from the power line (see, paragraph 2.4.12.). But this value may also differ downwards according to the EIC Chapter 2.4. clause 2.4.19. According to the rules, the input shield is installed at the border or territory of the applicant. From the introductory box, the marking of cable routes or power transmission poles to the place of work, power and lighting networks is already being done. For optimal distribution of power over the construction site, power wires are led to lifting mechanisms, to the concrete preparation area, to the woodworking area, to the place of welding work.

At the beginning of construction, the temporary lighting system may consist of several spotlights, and will be divided into main and emergency, local or general. You can learn more about it in our separate article.

Consumer connection diagrams

During the construction of the building, cable laying routes appear, the type and length of the cable, the characteristics of the loads are indicated, and a scheme for their inclusion is created. The connection scheme can be radial, ring, mixed wiring. Radial power is produced from one input, from which it is distributed by cables to power posts and lighting installations. If the developer has a backup generator, then the temporary power supply scheme will be ring or mixed type. The radial scheme is duplicated by the connection scheme from the generator set. This type of supply allows you to continue building in case of possible power failures.

Input design

One of our articles has already talked about self-reliance on a personal plot. The assembly technology of this shield is not much different, we recall the important points.

The meter and protection devices, such as, must be in a sealed box that prevents the ingress of moisture and foreign objects. It is also necessary to organize a grounding device, ground the shield and re-ground zero from the overhead power line (clause 1.7.61.), Organize the system (PUE chapter 7.1. clause 7.1.13). Do not forget to take all safety measures for the production of work.

Cable laying is possible both in trenches, in places where it will not experience loads from vehicles passing through it, and by hanging on a cable at a safe height. We recommend to study the technology in the country.

Security measures

Construction is always movement and movement, as a result of which unforeseen risks may arise. Therefore, there are special requirements for temporary power supply, since there is such a factor as the adverse effect of the atmosphere on the elements of electrical installations and their parts. Allied workers with a low tolerance group, or without qualifications, the presence of combustible and caustic materials at the construction site, the lack of grounding and potential equalization elements for electrical appliances.

When working in conditions of high humidity, it is necessary to follow the current rules of PUE 1.7.50-53, which prescribe protection, with indirect contact in cases where the voltage exceeds 50 volts AC and 120 DC. Also, to increase the safety of personnel working with power tools, it is necessary to use isolation transformers with a potential equalization system that combines all open cases using protective connectors in the socket.

When illuminating an object, the luminaires are selected with an IP54 protection class, for outdoor installation. By following our recommendations and current rules, you will minimize the risk of injury. Take care of yourself. Finally, we recommend watching a video that shows a shield for temporarily supplying the site with electricity:

That's all I wanted to tell you about what constitutes a temporary power supply for a construction site and what requirements are placed on it. We hope you found these basics useful and interesting!

Most types of construction work require electricity. This applies not only to power tools, but also to the lighting of workplaces, including in a construction trailer for temporary camp workers. Thus, it turns out that without preliminary electrical work and wiring, it makes absolutely no sense to start building facilities. Capital electrical works at the start of construction are fraught with the possibility that they may require significant changes as work progresses. Therefore, the most optimal option is temporary power supply of the construction site for the period of construction, but taking into account the design of electricians in accordance with the current requirements for electrical safety and other regulatory documents, including PUE and SNIP.

How to conduct electricity to a site with a place of proposed work, a construction site?

Before the start of the design, a technical assignment is issued to the design organization, in which it is necessary to provide:

• composition and power of loads;
• categorization of connected consumers;
• power source - overhead or cable lines, transformer substation or autonomous source;
• a plan for placing consumers and a layout for lighting fixtures.

Based on the terms of reference and local conditions, the design organization considers options for connecting electricity, receives technical instructions (TU) from the power supply company, makes the necessary adjustments and proposals that may relate to the construction of the necessary temporary mobile substations, the laying of overhead and cable power lines, taking into account uninterrupted power supply . Then a preliminary is made.

After the coordination of all the nuances, a preliminary design is created, a temporary diagram, and then the design is carried out in full, a single-line power supply diagram, a wiring plan are drawn up and all necessary approvals are carried out. As in the design of power supply for residential and industrial construction projects, working documentation is drawn up, and then as-built documentation, in which all changes made during the construction of temporary power supply devices and equipment are made.

Only after all the above actions have been carried out, it is possible to start construction in order to connect electricity to the construction site facilities.

The design of temporary power supply is most rationally carried out taking into account the purpose of the work and construction. With this approach, the cost estimate for the power supply of the constructed facility is greatly facilitated.

Requirements and features of temporary power supply of construction sites

There are some subtleties in the design and construction of temporary power supply:

• the electrical system must be flexible with the ability to quickly redistribute, temporarily connect and connect loads in accordance with the current stages of construction;
• minimum costs;
• work, emergency and security lighting of construction sites must be present;
• ensuring increased reliability and safety;
• laying of temporary cable power lines on supports or suspensions is required;
• connection of equipment and its inclusion should be carried out only by switching equipment with a class of dust and moisture protection according to IP at least 54 - 65.

Consumers of the construction site of a residential building or other facilities are mainly the following:

• welders;
• asynchronous motors of mechanisms and machines;
• equipment for heating concrete in cold weather.

Therefore, the need to include reactive power compensators in the project is not excluded.

Who can design

As well as the project for the power supply of the construction site, the calculation and drafting of the project for temporary power supply of the construction site must be entrusted to an organization that has the right to carry out the design. Thus, you can get a guarantee of safety, completeness of the developed project, well-organized electricity metering and save yourself from a lot of trouble in coordinating the project and approving the technical documentation and accepting the work performed.

The Mega.ru company is engaged in the development of all stages of design in Moscow and the Moscow region. The company's specialists also provide assistance in areas adjacent to the Moscow region. At some stages and for certain types of work, remote cooperation is provided throughout the Russian Federation. All prices for the production of work, as well as other necessary information, can be clarified at the coordinates posted on the page.

And you will find samples and standard projects of other objects in the relevant articles of our website.

Requirements:

1. Providing energy in the required quantity of the required quality;

2. Flexibility of the electrical network;

3. Reliability of the electrical network;

4. Minimization of electricity costs.

Design order:

1. Calculate electrical loads;

2. Choice of power source. Determination of the number and capacities of transformer substations;

3. Identification of an object of the first category requiring backup power supply;

4. Transformer substations, power and lighting networks, inventory electrical devices are placed at the SGP.

Purpose of the network - permanent and temporary power supply networks are designed for energy supply of power and technological consumers.

The initial data for the organization of temporary energy supply are the volumes, deadlines and structure of construction and installation works, the areas of temporary buildings, structures and closed warehouses, the size of the construction site, the types and capacities of construction machines, etc.

The design of temporary power supply is carried out in the following order:

Determine the consumers of electricity, the amount of required electrical power per shift for each consumer and the total required power of electrical installations or a transformer;

They select the appropriate type of transformer, set its location on the master plan and design a temporary power grid.

a- coefficient of power loss in the network;

Рс - capacities of power consumers;

Рт - capacities for technical needs;

Рсв - power consumption for welding transformers;

Moat - power consumption of lighting fixtures for indoor lighting;

Ron - power consumption for outdoor lighting;

cosj1 =0.7 - power factor for motors;

cosj2 =0.8 - power factor for technical purposes;

K - coefficients of simultaneous energy consumption:

K1=0.4; K2=0.4; K3=0.8; K4=0.9; K5=0.8.

1. Total power of motors for construction machines and mechanisms (SPc):

Tower crane BK 404M - 1 piece - 71 kW,

C-867 lift - 2 pieces - 24 kW,

Painting unit - 1 piece - 4 kW,

Various small mechanisms and tools - 5.5 kW

SPc = 104.5 kW

2. Total power of welding transformers (SPsv):

TS-500 Rs = 32 * 2 = 64 kW,

3. Power for indoor lighting (SPov):

closed warehouses

2 W / m 2 * 40 m 2 \u003d 80 W \u003d 0.08 kW

repair shop

15 * 25.23 = 378.45 W = 0.378 kW

offices and office space

15 * 48 = 0.72 kW

SPov = 1.178 kW

4. Power for outdoor lighting (SPon):

main aisles and driveways

210 * 5 = 1050W = 1.05kW

secondary passages and driveways

210 * 2.5 = 525W = 0.525kW

security lighting

2 * (70 + 30) * 1.5 = 300W = 0.3kW

open warehouses

7 * 50 * 2 = 700W = 0.7kW

installation lighting

760.3 * 3 = 2281W = 2.281kW

SРon = 4.856kW

5. Requirements for technological needs for an electric heater with a power of Pt = 500 kVA

We choose a transformer substation - SKTP-560 1 pc.

With P=560kVA.

Local estimate for civil works

Local estimate for special work

Local estimate for landscaping

Object estimate

Technical and economic indicators

1. Volume of the building - 37483 m3

2. Building area - 13154.4 m2

3. Total labor costs for all works - 23.828 man-days

4. The total estimated cost of construction - RUB 82.964.090

5. Estimated cost per unit area of ​​the building - 13.983 rub/m2

6. Estimated cost per unit volume of the building - 2213 rub/m3

7. Average output of one worker per day

· On general construction works - 3687 rub/person-days

On special jobs 1792 rub/person-days

In general, for the object - 3482 rub/person-days

8. Normative duration of construction according to SNiP - T n \u003d 360 days.

9. The actual duration of construction - T f = 352 days.

10. Construction time indicator -

PPP \u003d T f / T n \u003d 352 / 360 \u003d 0,98

List of references for the section:

1. SNiP 1.04.03.85 “Standards for the duration of construction and groundwork in the construction of enterprises, buildings and structures”.

2. SNiP IV-2-82 “Collections of elemental estimated norms for building structures and works”.

3. Teplichenko V.I., Terentiev O.M., Lapidus A.A. “Technology of construction production, course and diploma design”.

4. ENiP 4-1-1 “Installation of prefabricated and arrangement of monolithic reinforced concrete structures”.

5. Teplichenko V.I., Terentiev O.M., Lapidus A.A. "Technology of building processes".