220kV Aluminium Grading Rings For High Voltage Power Transformer Bushings Test
What is Aluminium Grading Ring?
Grading ring is widely used on different high voltage power and test equipment. Grading rings are similar to corona rings, but they encircles insulators rather than conductors. Although they may also serve to suppress corona, their main purpose is to reduce the potential gradient along the insulator, preventing premature electrical breakdown.
Product Description:
| Material |
Aluminum 6061, 3A21, steel and copper are main material for grading ring and other grading components production, Up to the selection of customers. |
| Wall Thickness |
2.5mm-8mm range standard or according to customers’ drawings |
| Production |
Aluminium Pipe Bending and Welding, Aluminium Pressure Die Casting |
| Voltage Grade |
10-1000kV |
| Outside Diameter |
300-2500mm or as customer’ design drawing requirements |
| Standard |
ASTM, DIN, ISO, Non-Standard or according to customers’ drawings requirement |
| Certifi cate |
ISO,SGS etc. |
| Applications |
Grading Rings can be used for power transformers, high voltage insulator, high voltage bushing test, arrestor, reactors, HVDC system, high voltage test laboratory etc.Corona Rings are used on the end fittings (line end or tower end) of post insulators and suspension insulators. |
| Packing details |
International standard package:
1.cartons are made according to size and shape of products.
2.products are packed in polybag in carton with tape sealed.
3.Cartons are on wooden pallet or case.
4.Packing and shipping as your request is available.
|
| Delivery time |
According to the quantity of grading rings but will as soon as possible |
| Payment terms |
L/C, T/T, Western Union
50% TT before the production, 50% before the shipment |
| Place of Origin |
Jiangsu, China |
How Grading Rings Work?
The potential gradient (electric field) across an insulator is not uniform, but is highest at the end next to the high voltage electrode. If subjected to a high enough voltage, the insulator will break down and become conductive at that end first. Once a section of insulator at the end has electrically broken down and become conductive, the full voltage is applied across the remaining length, so the breakdown will quickly progress from the high voltage end to the other, and a flashover arc will start. Therefore, insulators can stand significantly higher voltages if the potential gradient at the high voltage end is reduced.
The grading ring surrounds the end of the insulator next to the high voltage conductor. It reduces the gradient at the end, resulting in a more even voltage gradient along the insulator, allowing a shorter, cheaper insulator to be used for a given voltage. Grading rings also reduce aging and deterioration of the insulator that can occur at the HV end due to the high electric field there.
Condition of Aluminium Grading Rings Use:
- Ambient air temperatures within the range of -40 degree Celsius to +40 degree Celsius;
- Altitude above sea level not exceeding 1, 000m; (If the altitude is higher than 1, 000, it needs adjust. );
- Frequency of A. C. Power supply not exceeding 100Hz;
- The mechanical load no more than the rated value.
Grading Rings Application:
- GIS (Gas Insulated Switchgear)
- Arrestor
- HV bushing/Wall Bushing/Bushings/Insulator
- Power transformer/Instrument transformer/Current transformer/Voltage transformer
- Power cable
- High voltage test laboratory equipment
- HV capacitor
- Substation
- AC-DC converter
- HVDC systems
Packing Details:
We have the professional packing team for your grading rings container shipment.
With us, your money is safe, your grading rings cargo is safe.
Standard sea packing, The grading rings packing can be done by wooden case and cartons.
Inner Side packing, stretch film packing, EPE form packing, Bubble bag packing, grading rings surface finish Wrapping foam paper or plastic bag.
Outside packing, Layers of strength cartons, wooden case outside, stretch film packing outside cartons.
OTHER RELATED PRODUCT:
- Aluminium Corona Ring
- Aluminium Shielding Tube
- Aluminium Corona Cover
- Aluminium Conductor
- Aluminium Flange
- Aluminium Corona Sphere
