Power supply of 3-storey building

General data.

This working design of electrical lighting and power supply of the office building is made on the basis of :

• Specifications issued by Municipal Unitary Enterprise "City Electric Network "

• architectural and construction drawings;

The consumers of electricity are:

• electric lighting;

• household electrical equipment;

• office equipment.

In accordance with SPZ11102003, the electrical load is 60kW.

The total design input power consumption is 59.65 kVA.

Calculation of electrical loads is performed in accordance with SP 311102003.

Power supply

Power supply of the building is carried out from RU0.4kV by TP5 p / with "Central" three cables (2 VVGngLS brands 5х35 for providing the basic and one VVGngLS brand 5х5 for ensuring emergency power supply) in the earth. In TP5 RU-0.4kV 2 choppers of grade RPS2/250 are installed.

As main the switchboard of ShchRN36 of the Divnogorye plant of the low-voltage equipment with automatic BA61F29 switches and the VA57F35 switch is chosen

Category of power supply according to reliability requirements - III.

To ensure uninterrupted power supply of the automatic fire alarm system, the guaranteed power supply board is connected to the emergency power supply cable through the ALT (ALT 23).

Electric equipment

Power electric receivers are: electric lighting, computers and other office equipment.

Sections of supply and group networks are selected by design load current and checked by voltage loss.

Group networks are made in 3-wire version with cables of VBGng-LS grade:

• hidden under plaster

• in corrugated pipes behind suspended ceilings

• risers made in steel pipes

Switchgear boards 8505 are used as control and protection devices.

At power supply of several electric receivers from one group line, branch of protective conductor (PE) must be performed by soldering, welding, pressure testing, etc. Serial connection of grounding contacts of electric receivers to protective conductor is not allowed.

The design provides for the development of a single-line electrical circuit diagram for internal lighting, household and power socket networks.

The choice of types of lamps, their power and number are determined taking into account the categories of premises and sanitary standards. Lighting is provided by lamps with fluorescent lamps and incandescent lamps.

Room lighting is controlled by switches installed in the places available for control. Lighting of outputs is provided from emergency lighting network.

Accounting of electric power consumption is made according to PCL scheme and is provided on DCB and is carried out by two three-phase meters "Mercury 230AP-01CL," one of which is connected through a current measuring transformer, and the second directly. The meter must have a state check seal with a length of time of no more than 12 months.

Environmental conditions are normal. Air temperature + 15 + 250С throughout the year.

Grounding

In accordance with the requirements of PUE, Chapter 17, in order to ensure the safety of electrical installations, all non-current-carrying parts of electrical equipment that may be energized as a result of insulation failure must be reliably grounded.

This design uses the TNS type AC power supply system. Cable cores provided for this purpose are used as zero protective conductors (PE). SR distribution board is adopted with two buses N (working zero) and PE (protective zero).

According to PUE item 7.1.69, in order to equalize potentials, connect all metal bodies of boards, panels, metal bodies of process equipment, as well as metal pipelines of all purposes and metal structures of the building to the protective grounding buses.

In order to ensure safe operation of the electrical plant, this project provides for the following measures of protection against direct and indirect touching:

• Electrical installation of the building is equipped with a re-grounding device (PPE) of the protective zero conductor. For that grounding conductor with spreading resistance not more than 4 ohms is installed. Vertical electrodes made of angle steel 50x50x5, 2.5m long, are located at a distance of at least 1 meter from the foundation. The upper ends of the electrodes shall be at a depth of 0.7 metres from the surface and shall be joined together by a 40x5 steel strip by welding. The feeder from the SCP, with resistance not more than 4 ohms, is made of 3x16 HBGLS cable, connects the SCP to the PE bus of the switchboard of the SCP. In order to equalize potentials, construction metal structures, metal buildings of plumbing equipment, as well as pipelines of all assignments are connected to the grounding network.

• Connection of the DPC and the main line shall be made in a place convenient for maintenance and repeated operational measurements of the grounding conductor resistance.

• Automatic power-off;

• Use of safety shutdown devices

In the house, the main potential equalization system is performed in accordance with paragraph 7.1.87 of the PUE. An additional potential equalization system according to item 7.1.88 of the PUE is not required.

The design provides for automatic power cut-off, ensuring shutdown time in accordance with PUE requirements.

Lightning protection

Lightning protection device is made in accordance with "Instruction on lightning protection of buildings and structures" RD34.21.12287 and "Instruction on lightning protection of buildings, structures and industrial communications" SO 15334.21.1222003 in category III. Lightning receptors h = 3500 mm shall be made of round steel d = 12 mm, and placed on the roof. Round steel d = 8 mm shall be used as current leads. Install current leads at the corners of the building, connect to the grounding loop and lightning receptacles on the roof by welding.

Environmental protection activities

Disposal of spent gas discharge lamps is provided by submitting them to enterprises with special technological equipment for the neutralization of fluorescent, mercury and sodium lamps.

Organization of operation

The limit of balance sheet ownership and operational responsibility shall be determined by the act.

In accordance with PTE EP and MPOT RM, the electrical management shall be carried out by the person responsible for the electrical management with the safety team not lower than IV (deputy not lower than IV).

When replacing light sources, their rated power can be used not more than the lighting devices specified in the passport data. If this requirement is not met, the lighting device may be damaged (overheating) and ignited.

Scheduled repairs, preventive tests and reconstruction of the electrical network should be carried out by specialized organizations licensed for this type of work.

Installation Instructions

Installation of the electrical installation should be carried out by a specialized organization licensed for this type of activity.

Installation shall be performed in accordance with PUE and current regulatory documents.

List of hidden works, for which it is necessary to draw up acts:

- laying of cables under plaster,

- installation of extension and branching boxes

Вариант_ЭМ.dwg