Online solution to managing moisture levels in transformers

Excessive moisture is public enemy number one in power transformers utilising cellulose insulation with insulating oil for a long time.

Generator, transmission and distribution transformers are some of the most critical and expensive assets in a power network. They are very reliable and require relatively little maintenance in general since they have no continuously moving parts. However, there are chemical processes taking place and the insulating materials degrade with operation and time. Internal conditions ultimately determine the end of transformer life status. Excessive moisture will accumulate in the transformer’s insulation, where the majority of water is retained, thus increasing conductivity risk and accelerating ageing.

 

Take note

  • Moisture is a necessity in all cellulose materials, but too much is absolutely detrimental to the service life of power transformers.
  • Internal conditions ultimately determine the end of transformer life status and excessive moisture will accumulate in the transformer’s insulation.
  • Products are available that both monitor and indicate the moisture content of the system, and control moisture content.

 

Published as:

Controlling moisture levels in power transformers

By W Benecke and H Visser, Rotek Engineering

Electricity+Control, December 2011 (pgs 34 – 35)

Email:  VisserHC@eskom.co.za