DIN 42531 12-36kV Standard Porcelain Bushings(250A)
This series of products are medium-voltage cable-penetrating porcelain bushings designed according to the German industrial standard DIN 42531. They belong to the HV series and are mainly used in oil-immersed power transformers, serving as connection...
Product Profile
Product Overview
This series of products are medium-voltage cable-penetrating porcelain bushings designed according to the German industrial standard DIN 42531. They belong to the HV series and are mainly used in oil-immersed power transformers, serving as connection components between the winding leads and the external power grid, providing insulation and fixation.
The products cover three voltage levels: 12kV, 24kV, and 36kV, with a rated current of 250A. This standard was originally DIN 42531, which has now been aligned with EN 50180 and EN 50243 standards.
Product Features
DIN/EN Standard Compliance: Meets DIN 42531 and EN 50180/50243 standards, ensuring reliability and consistency in quality, size, and performance.
Composite Insulation Structure: This is the key difference between this series and low-voltage bushings. It features a solid porcelain body with oil-filled structure. The cavity between the conductor (copper rod) and the porcelain bushing is filled with transformer oil, greatly enhancing electrical insulation performance and effectively dissipating heat generated by high currents.
High-Quality Materials
Insulating Body: Made of high-quality ceramic (electro-ceramic), with excellent electrical insulation, high-temperature resistance, and weather durability.
Conductive Rod: Rigid cylindrical copper rod.
Highly Customizable: Manufacturers typically offer a wide range of custom services, such as extended conductive rods, special connectors, and special surface treatments, to meet customer-specific needs.
Main Applications
Core Application: Oil-immersed power transformers, usually installed on the low-voltage side of the transformer.
Installation Environment: Designed for both indoor and outdoor installations.
Technical Parameters
No. | Type | Factory Code | Color | Rated Voltage (kV) | Rated Current (A) | Creepage Distance (mm) | AC Dry (kV) | Weight(kg) |
1 | 10NF250 | 6295 | Brown(RAL8016) | 12 | 250 | 300 | 40 | 3.2 |
2 | 20NF250 | 6385 | Brown(RAL8016) | 24 | 250 | 445 | 40 | 4.6 |
3 | 20NF250 CD480 | 6385B | Brown(RAL8016) | 24 | 250 | 480 | 40 | 5.3 |
4 | 30NF250 | 6485 | Brown(RAL8016) | 36 | 250 | 600 | 40 | 6 |
5 | 30NF250 CD720 | 6485B | Brown(RAL8016) | 36 | 250 | 720 | 40 | 8 |
6 | 30NF250 CD900 | 6485K | Brown(RAL8016) | 36 | 250 | 900 | 40 | 9 |
7 | 30NF250 CD1320 | 6590 | Brown(RAL8016) | 36 | 250 | 1320 | 40 | 13 |
Selection and Considerations
Core Selection Basis: Primarily select the corresponding bushing specification based on the transformer’s maximum voltage (12kV/24kV/36kV) and rated current (250A).
Key Installation Dimensions: When selecting, verify the enclosure cover opening (Md) dimensions. For 250A specifications, the opening is M12×1.75.
Insulation and Pollution Resistance: Pay attention to the creepage distance parameter, which is a key indicator of pollution flashover resistance. The creepage distances for 12kV, 24kV, and 36kV are 300mm, 440mm, and 610mm respectively. This is an important selection factor in highly polluted environments.
Oil Level and Sealing: Since this is an oil-filled structure, ensure proper sealing between the bushing and the transformer cover during installation to prevent transformer oil leakage or external moisture ingress.
Corrosion Consideration: In corrosive environments, it is recommended to choose products with conductors that have special surface treatments like tin or silver plating to enhance corrosion resistance.