Release Date: 25 January 2005
Western Power is tackling the build-up of ash on powerlines from the recent Hills bush fires that has increased the risk of pole top fires and interruptions to power supplies.
Western Power General Manager Networks, Doug Aberle, said: "The priority will be high voltage 330/132kV transmission lines near fire and smoke affected areas on the eastern metropolitan and Yanchep areas to prevent flashovers and pole top fires."
Western Power has commenced line washing in the Yanchep area and preparing a program for continued line washing. In the mean time there remains an increased risk of pole top fires if high humidity or light rain occurs.
Helicopters will be used, where possible, to clean high voltage powerlines of the build-up he said.
Western Power is working closely with FESA and the Bureau of Meteorology to determine the extent of the smoke/ash distribution and advise on when they consider the fire to be extinguished. While the smoke haze exists it will continue to deposit ash and pollutants onto the powerlines.
Mr Aberle said the cost of the cleaning and line washing could extend to several hundred thousand dollars depending on the extent of the ash build-up. Line washing will continue for several months.
Flashovers occur mainly on transmission lines when, in combination with condensation or light rain, ash or dust build-up can cause arcing across insulators and dips and spikes in power supplies. This weakens the insulators and repeated arcing can cause the shut down of the powerline.
Pole top fires occur mainly on distribution lines when airborne material such as ash from bush fires, sea breeze salt or dust from the Wheatbelt settles on insulators on powerline cross-arms.
Condensation or drizzle absorbed by the build up of pollution can break down the effectiveness of the insulators.
In light rain or drizzle the electric current can leak from the conductors, track through the damp pollution build up onto the wooden cross-arms and into the timber.
The current heats up the timber which can, in some instances, result in a pole top fire.
The line washing program is in addition to Western Powerýs Siliconing program which aims to treat 40,000 poles over the next four years.
If you have any questions regarding this media release please email us: media@westernpower.com.au
Page update on 25 October 2006
