Outdoor distribution stations in concrete shells of up to 10 kV

Name	Value
Rated voltage on HV side, kV	6; 10
Rated voltage (line voltage), kV
at 50 Hz at 60 Hz	6,0; 10,0 6,6; 11,0
Rated current of main circuits of switchgear cabinets, A	630; 1000; 1600; 2000; 2500; 3150; 4000
Rated current of busbars, A	1000; 1600; 2000; 2500; 3150; 4000
Rated tripping current of circuit breaker built into switchgear, kA	12,5; 16,0; 20,0; 25,0; 31,5; 40; 50
Thermal resistance current (short-term current), kA	20,0; 31,5; 40; 50
Rated current of electrodynamic resistance of main circuits of switchgear cabinets (amplitude), kA	51,0; 64,0; 81,0; 102; 128
Thermal resistance current flow time, s	3
Rated DC voltage of auxiliary circuits, V:	110; 220
Rated AC voltage of auxiliary circuits, V:	220
Rated capacity of built-in auxiliary transformers, kV-A	1,25; 2,5; 4; 25; 40

Insulation strength of main and auxiliary circuits on the UHV side complies with the requirements of GOST 1516.1.

 Parameters and characteristics of distribution point shells

Name	Quantitative and qualitative indicators
Climatic version and placement category	Category 1 version N according to GOST 15150 and GOST 15543.1
Types of transportation and methods of transportation	– automobile; – railroad; – water (sea and river)

CSD, CSR, etc. cells have the possibility of docking with other types of switchgear, CSR, etc. cells respectively by means of transition panels.

The wiring of complete switchgear cabinets is carried out:

• for rated currents up to 1000 A inclusive aluminum busbars;
• for rated currents of 1600 A and above copper busbars.

Types of protection according to the customer's schemes.

Outdoor distribution stations in concrete shells have the following environmental durability parameters.

Nominal values of environmental climatic factors are as per GOST 15150 and GOST 15543.1, and:

• altitude above sea level should not exceed 1000 m;

• explosion- and fire-proof environment, free from conductive or abrasive dust, conductive or chemically active gases, vapors and sediments that destroy insulation and metals (atmosphere of type I and II according to GOST 15150);
• outdoor temperature is from -40 to +40 °С;
• relative humidity is up to 80%.

The construction of the shell of the outdoor switchgear enclosure complies with the Code of Practice (CP) 20.13330.2011 and withstands:

• wind pressure not less than 0.3 kPa;
• weight of snow cover on 1 m² of horizontal roof surface not less than 3.2 kPa with reliability factor 1.0;
• uniformly distributed loads on the floors not less than 2.0 kPa.

Shell structure provides protection of interior spaces from precipitation (intensity of up to 3 mm/min).

At the customer's request, it is possible to manufacture outdoor switchgears with seismic resistance of the structure up to 9 points according to the Code of Regulations 14.13330.2011. In this case, the equipment used to complete outdoor switchgears must meet the requirements for seismic resistance specified in the design documentation.

Class of structural fire hazard C0 according to the CoR 112.13330.2012.

Functional fire safety class F.5.1 according to the CoR 112.13330.2012.

Category of production premise is B4 as per Fire Code 105-03.

Building importance factor is 0.9 for buildings and structures of class IV in accordance with the “Requirements to safety factor for responsibility of buildings and structures during their designing”.

Outdoor distribution stations are not designed for use in mobile, mine and other stations.

Outdoor distribution stations provide:

• operation of installed high-voltage equipment;

• protection, automation and control of high-voltage equipment, incoming and outgoing feeders;
• remote control and monitoring of high voltage equipment;
• functioning of telemetering, security and dispatch communication systems;
• compatibility of remote control data transmission protocols in accordance with the recommendations of GOST R IEC 60870-5-101 and GOST R IEC 60870-5-104.

The requirements for compatibility of design solutions are met by using commercial equipment with standard and unified connection and fastening units, enabling rapid assembly, installation, adjustment and commissioning of the outdoor distribution stations.

High-voltage cells (single-end service assembled chamber, switchgear, etc.) of the same design type have the same overall and installation dimensions.

Withdrawable elements (if any) of high-voltage cells (single-end service assembled chamber, switchgear, etc.) of the same design are interchangeable.

Outdoor distribution stations meet the requirements for reliability and durability in accordance with GOST 20.39.312.

Outdoor distribution stations provide continuous operation of engineering equipment while unattended.

Mean restoration time upon the availability of emergency equipment is no more than 5 hours.

Specified service life of the outdoor distribution station is at least 25 years (subject to technical maintenance or replacement of equipment in accordance with the operating instructions for the outdoor distribution station and its components).

Reliability indicators of the main equipment (mean time between failures, probability of failure-free operation, etc.) - in accordance with the requirements of the technical conditions for the installed equipment.

 Specified no-failure operating time T_у is determined based on the field evidence for the equipment supplied to customers.

Failure criterion of the outdoor distribution station is a malfunction of high-voltage equipment or relay protection and automation, or damage to the insulation of the main circuits, resulting in undersupply of energy to the consumer.

Maintenance of the installed equipment and its repair are carried out using the spare parts kit supplied together with the equipment.

Outdoor distribution station corresponds to the requirements of GOST 22853 applied to the permanently installed facilities.

Reliability of the construction of outdoor switchgears complies with the requirements of the CoR 20.13330.2011.

The concrete shell of the outdoor distribution station building consists of an overhead concrete block (OCB) and, at the customer’s request, an underground concrete block (UCB). For standard sizes of OCB and UCB see table or they can be of individual sizes in accordance with the order.

OCB and UCB sizes

External dimensions of OCB, mm:
- width	2500, 3000*
- length	5000, 5500, 6000, 6500, 7000, 7500 (only at a width of 2500)
- height	2570, 2870*, 3070*
External dimensions of UCB, mm:
- width	2500, 3000
- length	5000, 5500, 6000, 6500, 7000, 7500 (only at a width of 2500)
- height	1520 (internal 1400), 1820 (internal 1700)
* - size (width x height) 3000 x 2870 mm - oversize 1 degree, 3000 x 3070 mm - oversize 2 degree of loading on rail transport..

OCB is a reinforced concrete structure with jointless floor and walls.

UCB is a rectangular reinforced concrete structure.

Concrete shell is made of high quality reinforced concrete. Strength quality of concrete - B35 (450 kg/cm²). Concrete frost resistance grade is F300.

The structure of outdoor distribution station is mechanically strong and ensures normal operating and transportation conditions without any residual deformations or damage preventing the normal operation of the outdoor distribution station.

All iron parts have anti-corrosion coating.

The components of the outdoor distribution station have a light gray paint coating. Upon the customer request, certain assembly units (doors, decorative elements) may be painted in other colours and marked with distinctive signs in accordance with the customer’s standards. The quality of painted surfaces corresponds to the IV coating class according to GOST 9.032.

The structure of outdoor distribution station enables to connect:

• overhead lines;

• cable lines;
• both cable and overhead lines.

Outdoor distribution stations with aerial cable line lead-ins are equipped with surge suppressors and the category of lead-ins corresponds to A or B according to GOST 9920.

Outdoor distribution stations are supplied fully assembled or in transport units prepared for assembly at the installation site without the need for disassembling the switching devices, checking the reliability of the bolted connections, as well as correctness of the internal connections. Components of outdoor distribution stations (transport units) equipped with mating connectors.

Doors from outdoor distribution station open towards other rooms or outwards.

Doors of outdoor distribution station rotate on hinges at an angle of at least 95º and have locks and handles. The handles are removable or combined with a key or latch. Doors must have drip strips.

The transport units of outdoor distribution station and cabinet sections are equipped with the structural elements for lifting and moving during installation. Lifting points are marked.

Outdoor distribution stations are installed on a flat surface, and can be fastened to the OCB by welding to embedded parts.

Outdoor distribution stations can be manufactured in two versions:

• single-module outdoor distribution stations, which are a reinforced concrete structure with equipment located inside;

• multi-module outdoor distribution stations, which are a reinforced concrete structure of two or more modules with equipment located inside. Modules are installed close to each other. On the HV side modules are connected by cable.

The OCB type of outdoor distribution station is equipped with doors for servicing and installing equipment included, as well as with the openings in the floor for:

• cable penetration;
• access of maintenance staff to the UCB.

The height of the room with the distribution station must be no less than the height of the high-voltage cells from the busbar inputs, jumpers or protruding parts of the cabinets, plus 0.8 m to the ceiling.

A lower height is permitted if replacement, repair and adjustment of high-voltage equipment, busbar inputs and jumpers is convenient and safe.

The width of the distribution station maintenance corridor ensures convenient servicing of the facility and movement of high-voltage equipment, and it should be no less than (in the clear between the fences): 1 m - for unilateral location of equipment; 1.2 m - for bilateral location of equipment.

If there are circuit breaker or disconnector actuators in the maintenance corridor , the above dimensions are increased to 1.5 and 2 m, respectively.

For corridor length up to 7 m, it is permissible to reduce the corridor width to 1.8 m in case of two-side access.

The width of the maintenance corridor for high-voltage equipment with withdrawable elements must provide easy control, movement and rotation of this equipment and its repair.

The width of the maintenance corridor for high-voltage equipment is determined on the basis of the following requirements:

• for single-row installation - the length of the largest of the cell trolleys (compact distribution device, single-end service assembled chamber, etc.) (with all protruding parts) plus at least 0.6 m;
• for double-row installation - the length of the largest of the cell trolleys (compact distribution device, single-end service assembled chamber, etc.) (with all protruding parts) plus at least 0.8 m.

If there is a corridor for the maintenance at the rear of high-voltage equipment, the width should be at least 0.8 m; specific local narrowings of no more than 0.2 m are permitted.

If there is an aerial cable line lead-in, the distance from the lowest point of the lead-in wire to the lowest point of the building foundation is at least 4.5 m.

According to paragraph 4.2.94 of the Electrical installation code outside distribution station has:

• at the length of the distribution station building up to 7 m - one exit;
• if the length of the distribution station building is from 7 to 60 m - two exits at its ends, it is allowed to make exits at a distance of up to 7 m from its ends.

Exits can be directly to the outside, onto a stairway, or to another production room of category G or D, as well as to other sections of the distribution station separated from this one by a fire door with the II degree of fire resistance.

There is one key for all doors of the distribution stations of the same voltage; the keys to the entrance doors of the distribution stations and other rooms must not fit the locks of the chambers, as well as the doors in the safeguarding of electrical equipment.

The external finish and painting of the accessory equipment meets the requirements of the technical specifications for the equipment. Differences in shades of paint color are allowed.

All other components have corrosion resistant coating.

The shell of distribution station can be painted according to customer requirements in colors and shades corresponding to the RAL scale.

The external and internal surfaces of the walls, roof and doors of the distribution stations are painted in color tones in accordance with the customer's requirements, and the coating meets the requirements for corrosion resistance and reliability.

The quality of painted surfaces corresponds to at least the IV coating class according to GOST 9.032.

The configuration of equipment and its components enable repair work without disassembling components not related to the repair being carried out.

The design of the distribution station excludes the possibility of free penetration inside through walls, doors, floor, roof and includes the following structural elements:

• reinforced concrete shell with jointless floor and walls, that ensures stiffness of distribution station;

• embedded parts for installation and wiring of the main and auxiliary equipment;
• doors with locking devices;
• cable channels that provide separate wiring of power and signal circuits in accordance with the Electrical Installation Code;
• cable entries that provide sealing gland of power and signal cable circuits into the cable channels of premises;

At the places of equipment installation there are necessary structural stiffening elements, as well as structural elements for its fastening, preventing deformation of the metal structure and damage to the equipment under loads arising during installation, transportation and seismic impacts.

The design of distribution stations ensures:

• preservation of specified thermophysical parameters of premises according to the CoR 60.13330.2012;

• free access of personnel and repair equipment to installed equipment, parts and units requiring maintenance and repair, as well as safe execution of repair work;
• the required workability during manufacturing and assembly at the plant, transportation, installation and operation;
• minimum weight of building structures due to the use of new efficient materials;
• optimal reliability and aesthetics of building structures.