Other Tests of Bushing
Temperature Rise and Thermal Stability Test
- Temperature rise test is carried out for bushings having rating below 132 kV.
- It is carried outdoor at normal power frequency voltage.
- The voltage is applied till temperature of bushing reaches steady state value.
- The temperature rise should be less than 40° C.Temperature rise is measured by suitable instrumentation system.
- Thermal stability test is carried out for bushings having rating 132 kV and above.
- The bushings are immersed in oil and voltage = √2 x (Working voltage of bushings) is applied.
- The losses taking place are dielectric losses, Cu loss in conductors, contact resistance etc.
- These are converted into heat. The bushing should withstand temperature rise without thermal run away.