Magistrate Kieran Gilligan handed down his ruling on Thursday after a complex special hearing that started in Warrnambool Magistrates Court earlier this week.

He said he agreed with the prosecution that any issues with the charges could be dealt with by the "provision of further particulars".

Particulars identify the act, matter or thing that is alleged to provide the foundation of a charge.

The prosecution was ordered to amend the charges on or before August 13.

The defence must apply for further particulars before August 20 with the prosecution required to respond within seven days.

The six charges related to two incidents, one involving clashing conductors at Terang that sparked what was known as the Terang/Cobden fire on St Patrick's Day, destroying more than 20 houses.

The second related to a power pole that snapped on a property at The Sisters, sparking a fire known as the Garvoc blaze, which wiped out at least two houses, 4000 hectares and livestock.

Mr Gilligan said Energy Safe Victoria (ESV) issued the charges on October 21, 2019 with a copy of the hand-up brief served on December 13 that year.

He said lawyers for Powercor did not make a "strike out application" until April 2021.

Mr Gilligan said the defence had never requested further particulars from the prosecution.

Earlier this week Powercor barrister Tim Margetts QC questioned the validity of the charges and applied on Monday for them to be struck out.

Mr Margetts said prior to the St Patrick's Day bushfires on March 17, 2018, Energy Safe Victoria made no complaints about Powercor and no recommendations that Powercor do anything differently.

Mr Margetts said both incidents, the clashing conductors and a snapped power pole, were "extremely rare events".

He said the clashing conductors at Terang was so "exceptionally rare" that evidence led in a civil trial revealed it was unknown to have occurred before.

He said under electrical safety installation regulations, poles must not lean more than 10 degrees from the vertical and the anchor pole at Terang was leaning to six degrees and therefore compliant with regulations.

But he said on the day of the St Patrick's Day Fires, reduced tension in a conductor caused the clash.

He said it was therefore important to understand or measure what the prosecution alleged constituted the breach of section 98 of the act.

Prosecutor Sally Flynn QC said major electricity companies were required to submit Electricity Safety Management Schemes (ESMS) to the state's energy safety regulator.

"It's their scheme that is submitted and if it reaches the threshold and reaches the requirements then it is then accepted by ESV. That's the process," she said.

"It is a process and outcome-based regulatory approach which is slightly different to that in the Occupational Health and Safety arena that we're perhaps more familiar with."

The prosecutor said Powercor's duties were not delegatable.

"The duty in this case under section 98 is on the accused to design, construct, operate, maintain and decommission its supply network to minimise as far as practicable the hazard and risks to the person, property and bushfire danger," she said.

The matter was listed for a special mention on June 3.

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