Over 2015, the Victorian Government undertook a world-first test program which conclusively demonstrated the capabilities of a range of fully optimised Rapid Earth Fault Current Limiter (REFCL) technologies in reducing bushfire risk as a result of powerline faults or breakages.

This research at Kilmore South was conducted in partnership with the Victorian electricity distribution businesses , confirming and refining the findings of the Powerline Bushfire Safety Program's (PBSP) 2015 Frankston trial of REFCLs.

This page provides information on each stage of the research findings.


The REFCL is a class of technology used primarily for supply reliability outside of Australia. In 2011, the Victorian Government's arc-ignition research indicated that REFCLs could reduce powerline fire risk on Victoria's rural distribution network.

The 2014 Frankston and 2015 Kilmore South tests were carried out under simulated worst-case Black Saturday conditions and demonstrated the capacity of REFCLs to prevent faulted 22 kV powerlines from starting fires.

How do they work?

REFCLs can detect phase-to-earth faults. They then cancel the voltage on the fault within milliseconds of detecting it and limit the voltage of the fault to below the point where it can start a fire.

Frankston South Trials

In 2014, trials were conducted on a live electricity distribution network and conclusively demonstrated that REFCLS are able to reduce fault current almost instantaneously reduced on wire-to-ground faults, while maintaining the power on for un-faulted phases.  Power was restored immediately when the fault cleared. These tests established considerable potential to reduce the risk of starting a fire and customer supply interruptions.

Kilmore South Trials

The Kilmore South Rapid Earth Fault Current Limiter (REFCL) technology trials took place through 2015 and compared the effectiveness of a range of REFCLs to reduce the bushfire threat from faults on 22 kV powerlines. These world-first trials confirmed and refined the performance standard to respond to network faults and revealed the optimal REFCL technology configuration for the Victorian network.

Download Word Version of the Report:
(Due to the report's large file size, the Word version of the REFCL Kilmore Final Report has been separated into sections.)

POWERLINE BUSHFIRE SAFETY PROGRAM - Ignition tests -lo sag conductor

Earth fault on typical Neutral Earth Resister

This filmed test of a powerline falling to the ground simulates the fire start potential of networks under non-REFCL protection systems.

Protected network: 18A fault current into soil, rising to 24A over 0.9s.

Earth fault on REFCL

This filmed test confirms that REFCL technology reduces the powerline arcing from a fallen conductor, dramatically reducing the risk of fires associated with bare-wire 22kV overhead powerlines. The test was performed under worst case fire weather conditions, such as those experienced on Black Saturday 2009.

Protected network: fault current into soil 15A peak falling to zero in 55ms, no current on second bounce or beyond.

Where to next?

The results of the REFCLs tests have assisted the Victorian Government and electrical distribution businesses to develop and implement the regulated introduction of REFCL technology onto the Victorian network through amendments to the Electricity Safety (Bushfire Mitigation) Regulations 2013 which commenced on 1 May 2016.

REFCL Trial Report

The report outlines the results of tests carried out for the Powerline Bushfire Safety Program at a purpose-built facility in Frankston, Victoria in the first half of 2014 in accordance with an Agreement between Marxsen Consulting Pty Ltd and the Victorian State Government.

This report contains test results, observations, analysis, commentary and interpretation.

Due to the report's large file size, the PDF version of the REFCL Report has been separated into sections:

Page last updated: 17/02/20