EN 50386 1KV Standard Porcelain Bushings(250-4500A)
This series strictly follows the European standard EN 50386 (Bushings up to 1kV and from 250A to 5kA, for liquid filled transformers) design. It is a type of low-voltage ceramic insulated bushing, mainly used as a lead bushing for liquid-immersed transformers...
Product Profile
Product Overview
This series strictly follows the European standard EN 50386 (Bushings up to 1kV and from 250A to 5kA, for liquid filled transformers) design. It is a type of low-voltage ceramic insulated bushing, mainly used as a lead bushing for liquid-immersed transformers (usually oil-immersed), ensuring safe connection between the transformer's interior and the external power grid.
The product covers a wide rated current range (250A-5000A), meeting the needs of transformers of different capacities. The EN 50386 standard has been adopted as a national standard in several European countries, such as BS EN 50386 in the UK and DIN EN 50386 in Germany.
Core Technical Parameters (250A-4500A)
Rated voltage: up to 1000V. According to the standard, these bushings are also suitable for operation at 1.1kV voltage.
Rated current: from 250A to 5000A. The current levels explicitly covered by the standard include: 250A, 630A, 1250A, 2000A, 3150A, 4000A, and 5000A.
Frequency: Suitable for grid systems from 15Hz to 60Hz.
Minimum creepage distance: varies depending on product design, ranging from 55mm to 140mm.
Main insulation material: Ceramic (Porcelain).
Bottom component material: can be plastic or ceramic.
Porcelain color: usually brown.
Product features
Compliance with EN standards: Complies with EN 50386 standards, ensuring product quality, dimensions, and performance reliability and international acceptability.
Designed specifically for immersion transformers: The product is optimized for operation in insulating liquids such as transformer oil.
High-quality ceramic insulation: Using high-quality ceramics as the main insulating material, it offers excellent electrical insulation, high-temperature resistance, and weather resistance.
Highly customizable: Manufacturers usually offer flexible customization services, offering not only standard current ratings but also products with intermediate current values such as 800A, 1250A, 1600A, 2500A, 4000A, and 4500A.
Clear structure: The product structure is usually divided into top porcelain parts and bottom components (plastic or ceramic).
Main applications
Core application: Immersion distribution transformer, used as a low-voltage side lead wire bushing.
Other applications: Also suitable for other low-voltage power equipment that requires a casing to pass through the oil tank or casing.
Technical specifications
No. | Type | Factory Code | Material | Color | Rated Voltage (kV) | Rated Current (A) | Creepage Distance (mm) | AC Dry (kV) | BIL (kV) | Standard |
1 | EN 1/250 A | 1/250 A&EN | Porcelain | Brown(RAL8016) | 1 | 250 | 50 | 10 | 20 | EN 50386 |
2 | EN 1/630 A | 1/630 A&EN | Porcelain | Brown(RAL8016) | 1 | 630 | 75 | 10 | 20 | EN 50386 |
3 | EN 1/1000 A | 1/1000 A&EN | Porcelain | Brown(RAL8016) | 1 | 1000 | 75 | 10 | 20 | EN 50386 |
4 | EN 1/2000 A | 1/2000 A&EN | Porcelain | Brown(RAL8016) | 1 | 2000 | 75 | 10 | 20 | EN 50386 |
5 | EN 1/3150 A | 1/3150 A&EN | Porcelain | Brown(RAL8016) | 1 | 3150 | 75 | 10 | 20 | EN 50386 |
6 | EN 1/4500 A | 1/4500 A&EN | Porcelain | Brown(RAL8016) | 1 | 4500 | 75 | 10 | 20 | EN 50386 |
7 | EN 1/250 B | 1/250 B&EN | Plastic | Brown(RAL8016) | 1 | 250 | 50 | 10 | 20 | EN 50386 |
8 | EN 1/630 B | 1/630 B&EN | Plastic | Brown(RAL8016) | 1 | 630 | 75 | 10 | 20 | EN 50386 |
9 | EN 1/1000 B | 1/1000 B&EN | Plastic | Brown(RAL8016) | 1 | 1000 | 75 | 10 | 20 | EN 50386 |
10 | EN 1/2000 B | 1/2000 B&EN | Plastic | Brown(RAL8016) | 1 | 2000 | 75 | 10 | 20 | EN 50386 |
11 | EN 1/3150 B | 1/3150 B&EN | Plastic | Brown(RAL8016) | 1 | 3150 | 75 | 10 | 20 | EN 50386 |
12 | EN 1/4500 B | 1/4500 B&EN | Plastic | Brown(RAL8016) | 1 | 4500 | 75 | 10 | 20 | EN 50386 |
Selection and precautions
Core selection criteria: The primary consideration is to select the corresponding bushing specification based on the transformer's rated voltage (up to 1kV) and rated current (250A-4500A).
Pay attention to creepage distance: Choose a model with sufficient creepage distance based on the installation environment's dirt level, which is a key parameter to prevent flashover.
Confirm operating voltage: Although the standard rated voltage is 1kV, bushings are also suitable for operating voltages of 1.1kV. When selecting, confirm the actual system voltage.
Sealing and installation: During installation, ensure a good seal between the sleeve and the transformer box cover to prevent leakage of insulating liquid.