High-voltage bushings vst, vsta, vstb. Inputs to power transformers

Removable high-voltage transformer bushings are used to connect power transformer inputs to conductors of external electrical networks.

Our company is also a supplier of components for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings.

Design of transformer bushings:

Transformer bushings consist of a porcelain insulator, a current-carrying rod ( input studs), seal parts and support elements for seals, fastening elements (nuts and washers) and are manufactured according to the technical requirements of the drawings.

Inputs are installed on the cover or wall of the transformer tank in input installation designs that have additional parts for securing the input: bosses, fasteners, flange, cams, gaskets and disk (tank plug for transport if the input is dismantled).
The entries are installed at an angle to the vertical from 0° to 90° inclusive. Continuous cantilever input loads comply with IEC 60137.

High-voltage bushings installed on the transformer are operated under pressure from transformer oil in the transformer conservator. All inputs are removable and allow replacement during operation. bushing insulator IPT, if necessary, without dismantling the current-carrying rod (input pin).

The service life of the bushings is 25 years.

The main malfunctions of transformer bushings are as follows:

Research and Production Association "EnergoKomplekt" will also help deliver VST, VSTA transformer bushings to any point in Russia, as well as neighboring countries by road or rail.

For any questions you may have, please contact:

Description

Manufacturing of transformer bushings for HV (VSTA) and LV bushings (VST) is one of the leading areas of our company. High-voltage transformer removable bushings are used to connect power transformer bushings to conductors of external electrical networks. Our company is also a supplier of components for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings. Design of transformer bushings: Transformer bushings consist of a porcelain insulator, a current-carrying rod (input pin), sealing parts and support elements for seals, fastening elements (nuts and washers) and are manufactured according to the technical requirements of the drawings. Inputs are installed on the cover or wall of the transformer tank in input installation designs that have additional parts for securing the input: bosses, fasteners, flange, cams, gaskets and disk (tank plug for transport if the input is dismantled). The entries are installed at an angle to the vertical from 0° to 90° inclusive. Long-term cantilever loads on the bushing comply with IEC 60137. High-voltage bushings installed on the transformer are operated under the pressure of transformer oil in the transformer expander. All inputs are removable and allow replacement of the IPT bushing insulator during operation, if necessary, without dismantling the current-carrying rod (input pin). The service life of the bushings is 25 years.

Transformer bushing VST, VSTA VSTA 6-10/250 (HV bushing) Manufacturing of transformer bushings for HV (VSTA) and LV bushings (VST) is one of the leading areas of our company. High-voltage transformer removable bushings are used to connect power transformer bushings to conductors of external electrical networks. Our company is also a supplier of components for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings. Design of transformer bushings: Transformer bushings consist of a porcelain insulator, a current-carrying rod (input pin), sealing parts and support elements for seals, fastening elements (nuts and washers) and are manufactured according to the technical requirements of the drawings. Inputs are installed on the cover or wall of the transformer tank in input installation designs that have additional parts for securing the input: bosses, fasteners, flange, cams, gaskets and disk (tank plug for transport if the input is dismantled). The entries are installed at an angle to the vertical from 0° to 90° inclusive. Long-term cantilever loads on the bushing comply with IEC 60137. High-voltage bushings installed on the transformer are operated under the pressure of transformer oil in the transformer expander. All inputs are removable and allow replacement of the IPT bushing insulator during operation, if necessary, without dismantling the current-carrying rod (input pin). The service life of the bushings is 25 years.

Removable bushings such as VST, VSTA, VSTB are used in power transformers to connect transformer windings to conductors of external electrical networks located in the open air or in closed bus systems. Operating conditions: moderately cold climate, the environment is non-explosive and does not contain conductive dust, aggressive gases and vapors in concentrations that can lead to the destruction of electrical porcelain and glaze.

The high-voltage bushing is a structure with external and internal insulation. The design of internal insulation has a great influence on General characteristics insulation of high-voltage input. Insulation and the quality of its manufacture largely determine the reliability and, accordingly, the service life of a high-voltage bushing.

The basis of the high-voltage bushing is a porcelain insulator, in the inner hole of which a current-carrying copper rod is threaded and hermetically secured. The top contact of the copper rod is used to connect to external electrical networks, and the bottom contact is for connection to the winding taps. It is allowed to mount the inputs on the cover or wall of the transformer tank at an angle of no more than 90 degrees. Inside, the high-voltage input is filled with oil and is always under slight excess pressure created by the oil level in the conservator. The upper and lower input contacts are tin-plated.

Dimensions of inputs

According to the method of connecting to the winding outlet, high-voltage bushings are produced in the following design, for example VSTA-1/2500-1 (dismountable version), VSTA-1/2500-2 (non-separable version)

Power transformers use removable bushings that connect the windings to the conductors of external electrical networks. Networks can be located both outdoors and in closed systems. The main condition is that the environment must be non-explosive and free of conductive dust, as well as without such concentrations of aggressive vapors and gases that can damage electrical glaze and porcelain.

Transformer bushings are bushings made of porcelain. A current-carrying rod with two contacts is passed through the internal hole of the insulator: the upper one is intended for connection to external electrical networks, and the lower one is used for contact with the winding taps.

Input installation conditions

• The bushings are installed on the wall of the transformer tank or on its cover.
• When installing, an inclination from vertical to 90 degrees is allowed.
• The internal cavity of the transformer input is always under slight excess pressure (it is created due to the oil level in the expander).

The bushings can be produced in collapsible and non-dismountable versions.

Scientific and production association "ElectroKomplekt" produces VN bushings (VSTA-10/250) to a 25-2500 kVA transformer, as well as the following types of LV bushings:

• VST-1/250 (25-160 kVA);
• VST-1/400 (250 kVA);
• VST-1/630 (400 kVA);
• VST-1/1000 (630 kVA);
• VST-1/1600 (1000 kVA);
• VST-1/2000 (1600 kVA);
• VST-1/2500 (2000 kVA).

We ourselves are engaged in the production of removable inputs for transformers, and all listed models are in stock. Bushings for voltages of 20, 35 and 110 kVA are manufactured only to order. Products are made from rolled and cast brass, aluminum or copper. It is possible to produce both piece and mass versions of the product according to customer drawings.

Letter marking of transformer inputs

• VST - removable transformer input.
• A and B - categories of equipment.
• U - version for temperate climates.
• HL - version for cold climates.
• T - version for tropical climates.

Numerical designations:

• in the numerator - rated voltage (kV);
• the denominator is the rated current (A);
• number after the fraction: 1 - dismountable connection of the input rod with the winding, 2 - non-separable.

For more information or to place an order, call the numbers provided.

Types of inputs

Input 6–10 kV for outdoor installation, 800 A

Input weight 8.6 kg; flange weight 5–3.18 kg. At rated current 1200 A, an input is used that differs from the input in the dimensions of the stud: stud - 1 has a diameter of the MZO with a blade with dimensions as for a current of 1200–1400 A; total length of the pin is 585 mm. With this stud the input weight is 10.6 kg

1. copper hairpin
2. brass cap
3. porcelain insulator
4. rubber washer
5. brass flange
6. bolt with diameter M12
7. slotted plate
8. electric cardboard washer
9. copper washers
10. low brass nut

Input 6–10 kV for outdoor installation, 600 A

Input weight 7.65 kg; flange weight 9–2.7

1. copper hairpin
2. low brass nut
3. copper washer
4. cast brass cap
5. washer (rubber size 0 68/98×6 mm)
6. magnesia cement
7. porcelain insulator
8. rubber washer dimensions Ф 98x134x6 mm
9. cast iron flange
10. pin with diameter M12 (6 pcs.)
11. rubber washer size Ф 130/155X6 mm
12. electric cardboard washer size Ф 55/80×2 mm
13. copper washer size Ф 22/75×5 mm

Input 35 kV for outdoor installation, 400 A

Input weight 22 kg; flange weight 13–7 kg

1. copper hairpin
2. low brass nut
3. copper washer
4. M6 steel screw
5. rubber washer size 98/134×6 mm
6. magnesia cement
7. porcelain insulator
8. cast iron cap (weight 1.78 kg)
9. insulator No. 2031
10. paper-bakelite tube Ф 18/ЗОx640 mm
11. rubber washer Ф 140/188X6 mm
12. cast iron flange
13. steel pin M12 (8 pcs.)
14. rubber washer Ф 175/210×6 mm
15. electric cardboard washer
16. getinax washer Ф18/65×15 mm

Production time for removable transformer bushings: from 5 working days.