How to increase lifetime of ceramic isolators on 66 kV line? 4

[SA07]

Hi

What is the approx. lifetime of ceramic isolators on 66 kV line?
How can we maintain properly these isolators? Cleaning with what product?

Please see attached picture.

 

[RRaghunath]

Ceramic or Porcelain insulators need to be washed periodically to prevent pollution related discharges / flashovers.
The other and long lasting solution is applying silicone grease on the insulators. This grease prevents water to form a continuous tracking path on the insulators.
Best fit-and-forget solution is replacing the insulators with silicone rubber based polymer insulators. The performance of these insulators in highly polluted environment is well established now.

 

[SA07]

Thanks Raghunath.
Someone working at the utility company told me that birds eat away the skirts on the silicone insulators. Has anyone also encountered this problem?
Is it recommended to replace all ceramic isolators after years of use? Ours are in service since 2007 (14 years.

 

[OffTap100]

Is it recommended to replace all ceramic isolators after years of use? Ours are in service since 2007 (14 years."

Are they located in a area of heavy pollution? Heavy industry, cement plant/quarry etc?

Although are system is slowly changing over our transmission and distribution to composite or silicone insulators. 14 years? We have ceramic and glass insulators that are at least 50-70 years old. Transmission is cleaned with RO water, using proper pressure from purpose designed equipment.

OT

 

[bacon4life]

Ceramic insulators should last many decades. We used to wash transmission insulators due to industrial pollution. Tighter air pollution laws have dramatically reduced pollution in my area and we no longer have to wash insulators.

Birds eating insulator skirts is not something I had heard of. It would be interesting to hear if it was confined to a single species of birds, or perhaps a single model of insulator.

Live line washing can be done using deionized water, corn cobs or walnut shells.