Powerline directive: Powercor and AusNet told to inspect SWER lines for fire faults

Energy Safe Victoria has told Powercor and AusNet to inspect powerlines for defects that risk sparking fires, after it was revealed there were anomalies left unattended.

A faulty SWER line sparked the Kilmore fire that killed 119 people on Black Saturday 2009, caused 232 casualties and destroyed 1242 homes.

Energy Safe Victoria has contacted Powercor and AusNet, calling on the electricity distributors to investigate 21 anomalies on 1000km of their single wire earth return powerlines, which are likely to include two to three defects that pose an immediate fire risk.

Energy Safe chief executive Leanne Hughson said: “We have contacted distribution businesses to ensure they investigate all the anomalies identified to determine if they are genuine faults and if so, rectify them”.

The Weekly Times reported yesterday that over the past six months, scans of 67 sub-networks using electrical fault detectors found 34 anomalies across 1000km of SWER lines.

But only 13 of those anomalies have been inspected to date, with two major fire risks found – one a detached conductor and the other an intermittent tree contact, which have since been remedied.

It was a broken conductor that the 2009 Victorian Bushfires Royal Commission found sparked the Kilmore East fire that killed 119 people, caused 232 casualties and destroyed 1242 homes.

Aerial pictures of fire devastation in Kinglake West in 2009, from a fire sparked by a faulty SWER line at Kilmore East.

Based on the current rate of detections, the remaining 21 anomalies are likely to include two to three more defects that pose an immediate fire risk once inspections are completed.

The ESV directive raises question about the remaining 29,000kms of SWER lines that are yet to be scanned using the Electric Fault Detection technology, developed by IND Technology and tested over the past four years in a collaboration with Powercor, AusNet and the Victorian Government.

An IND.T report on the 1000km scan found “SWER powerlines had an average of one anomaly per 30 powerline-kilometres in six months” and about three to four serious defects that posed a major fire risk every 1000km.

The report found “there are likely 85 to 120 serious fire-risk defects currently awaiting detection on SWER powerlines across Victoria”.

IND.T chairman Professor Tony Marxsen said after five years’ of research and field trials the EFD technology was ready to roll out, with manufacturing runs already underway to meet US and Canadian power companies’ orders.

But neither PowerCor nor AusNet support a roll out in Victoria, with both arguing more work needed to be done on the EFD technology in Australia.

“We recognise that this technology has been reported as successful in the USA, however their network is very different to ours,” an AusNet spokeswoman said.

“For example, they do not have REFCL (Rapid Earth Fault Current Limiter) technology installed, and their network is not in as good a position as ours, which is a result of our investment in maintenance and replacement programs over many years.”

However Professor Marxsen said EFD had already been installed on US networks with REFCL and worked.

He said the technology could also pick up broken tie-wires, detached conductors, contact with vegetation, failing and broken insulators, failing splices, loose clamps and broken conductor strands, all of which posed fire risks.

A Powercor spokesman said: “We are supportive of this type of technology and have trialled it across parts of central and western Victoria.

“(But) while this technology is promising, we are still testing and analysing how effective it is. We need to make sure these devices are accurately detecting faults and that our network is set up to support a broader rollout so we are delivering for our communities.”

Ms Hughson said ESV was aware of the findings from the interim report into the trial of the IND-T electrical fault detector technology.

“We expect that distributors who are testing this technology will carefully assess the product’s features, functionality, compatibility, cost and benefits to determine whether it reduces safety risk on their networks and its suitability for broader usage,” she said.

At this stage ESV has given no further directives, but both Powercor and AusNet are required under Victoria’s Electricity Safety Act to “design, construct, operate, maintain and decommission its supply network to minimise as far as practicable the bushfire danger arising from the supply network”.

IND.T’s earlier reports on EFD puts the cost of installing the technology across the entire SWER network at $30 million, equating to 7500 units at $3000 each, plus $1000 for installation, plus an annual $6 million service fee.

The Victorian government, distributors and electricity customers have already spent about $1 billion REFCLs at substations servicing 22,000kV lines, plus even more on some limited insulation and undergrounding of lines.