Testing of Bushings
Q. Describe in brief various tests carried out on ‘Bushings’.
- Bushings are insulators that are generally used on high voltage side of transformer. H.V. side connection
- The bushing is hollow and half of its portion enters transformer tank as shown. The HV winding connections are carried through bushings and brought out from top.
- The entire HV test on bushings are tabulated as below in Table.
|
Item |
Test Category |
Sr. No. |
Test to be performed |
|
Bushings |
Power frequency test |
1. |
Power Factor tests |
|
2. |
Partial discharge test |
||
|
3. |
Wet power frequency voltage withstand test. |
||
|
4. |
Momentary power frequency voltage withstand test. |
||
|
5. |
Visible discharge test. |
||
|
Impulse test |
6. |
Dry lightening impulse voltage withstand test |
|
|
7. |
Dry or Wet switching impulse voltage withstand |
||
|
Other tests |
8. |
Temperature rise and thermal stability test. |