Tim Tobin, SC, opened the Maddens Lawyers class action case for lead plaintiff Anthony Lenehan in the Supreme Court sitting at Warrnambool on Monday.

He claimed that an anchor pole in a clay drain shifted on Bourkes Road, causing the conductors to come closer, exactly what had happened previously, and prompted Powercor to straighten the same pole in 2007.

Mr Tobin also claimed the conductors did not meet the ground clearance standard above the Princes Highway, in places being more than one metre short.

He said clashing conductors at pole No. 3 near the Terang electrical substation led to molten metal falling to the ground and sparking the devastating bushfire on St Patrick's Day last year.

The fire burnt 18 kilometres in a south-easterly direction, burning 4000 hectares, 90 properties, homes, sheds, fences and livestock.

Mr Tobin said the conductors should have been 900mm apart but were only 210mm apart, a "grossly insufficient clearance" and if Powercor complied with its own standard the fire would never have started.

He said Powercor's own Light Detecting and Ranging Measurement data showed there was a gross breach of regulations but the electricity distributor did not instruct anyone to look at the data.

They looked at data for 66kv lines but not 22kv lines.

"No one bother to look at the 22kv lines," he said.

"Powercor never looked at the risk of clashing. It would have been obvious to anyone looking at clearances."

Mr Tobin said clashing conductors had been a major cause of bushfires since the 1970s and Powercor admitted its assets caused the Terang/Cobden bushfire.

He said on Black Saturday 2009 clashing conductors caused a bushfire at Weerite, just 30 kilometres east of Terang.

Barrister Tim Margetts, QC, said there was no argument that Power had a duty of care but the dispute was whether plaintiffs had the right to claim damages.

He said Powercor had an obligation to inspect and maintain its assets..

"In this trial we say that from a Powercor perspective, Powercor has discharged that duty," he said.

Mr Margetts said the question was whether Powercor had discharged its duty and exercised reasonable care.

He said there were risks in the supply of electricity that could not be completely eliminated and not all potential risks could be prevented or all risk removed.

The barrister said a management scheme had been put to and accepted by Energy Safe Victoria.

Mr Margetts said classing conductors on poles with such cross arms were "exceptionally rare" and experienced linesmen had described it as "unheard of".

"The court has to consider if the the inspection and maintenance pratices introduced by Powercor discharge the duty of care," he said.

The QC said the clash of conductors happened 2.5 metres from the power pole, not at the pole.