No down time for business with live line hot sticks

Darwin is known as the lightning capital of the world and the power network in the Top End can receive up to 33,000 lightning strikes a year causing damage and blackouts.

As part of its ongoing maintenance and upgrade program, Power and Water is further protecting the 66kV line along the Arnhem Highway using ‘hot sticks’, a live line procedure to changeover insulators.

Power and Water estimate that 40% of units tripping and causing power outages in this area are caused by lightning strikes which affect not just residents but big operations such as the Mt Bundy and Tom’s Gully mines. Other causes are from trees and animals coming into contact with the lines.

The $350,000, six week project along a distance of 50 kilometres, involves 280 power poles from just near Lambells Lagoon to the other side of the Mary River and will improve supply reliability in an area prone to flashovers (arcing or sparking between two or more adjacent conductors).

While any live power system is dangerous, the five man line crew are highly skilled and trained to carry out this technique safely. The technique involves lifting the conductors on the cross arms with a 55 tonne crane (to get the reach required) and changing over current insulators to the new polymer style ones while the system is live. Using a live line method enables the power to remain on for customers while it is being worked on.

The newer style insulators are less prone to cracking and getting moisture inside them, making them tougher and less likely to be blown apart with a direct lightning hit.

This delicate operation involves the crane hook, insulated itself, taking the weight of the live line and holding it in position. The old insulator is hooked with a ‘hot stick’, the securing pin knocked out and it swapped over for the new insulator. This operation is repeated on all three insulators on each pole and is hot, exhausting work for the crew up in the bucket, observers on the ground and the crane operator.

Contact:
Judie Brennan
Media Manager,
Corporate Communications
Power and Water Corporation
Phone: 08 8985 8481