When they operate, crews patrol the line to determine the cause of the fault and ensure it is safe for the community before switching power back on.
Under our Bushfire Mitigation Plan, we manage assets and risks that could cause fires due to:
Natural disasters such as bushfires, floods or extreme weather events may also trigger one or many of these causes of ignition risk.
Rapid Earth Fault Current Limiters (REFCLs) are another part of our bushfire mitigation strategy. The technology helps to reduce the likelihood of powerline-related bushfires by operating like a large safety switch. It detects when one line out of a three-phase powerline has fallen to the ground and almost instantly reduces the voltage on the fallen line. At the same time, it boosts the voltage on the two remaining lines in service. This means we can maintain power to homes and businesses while substantially reducing the fire risk.
The introduction of REFCLs was part of the Government’s response to the 2009 Victorian Bushfires Royal Commission.
Powercor now has 22 REFCLs operating across 135 feeders and protecting more than 17,800km of powerlines and 289,000 homes and businesses in many communities.
And they’re not just helping prevent bushfires. We’ve also found important other safety benefits. For example, REFCLs have activated when operators of heavy machinery such as excavators or bulldozers accidentally hit overhead powerlines while working – protecting the operators.
After a few moments, the device checks if the fault is still active. If it is temporary, then power is restored to the line. If it is a continuing fault, power to all three lines will be shut off to protect against fire risk and make it safe for our crews to fix.
Our team works year-round to keep our network safe and reliable. The info below is a guide to some of the most common safety devices or inspection activities you’ll see on or around our networks or hear about and they represent just part of our comprehensive approach to network safety.
For further information, download the network safety factsheet at the bottom of this page.
Aerial inspection
Helicopters fitted with advanced laser detection technology inspect the entire network of powerlines every year. They are scanning and detecting vegetation growing near powerlines to inform our tree cutting program.
Auto Circuit Recloser (ACR)
These devices are circuit breakers for Single Wire Earth Return (SWER) lines and other types of powerlines. If an object, such as an animal or tree branch, falls on a wire, the ACR will turn off and on for a few short periods until the object falls clear of the line and supply is restored. If the object does not clear, the power will remain off until a crew locates and repairs the fault.
During Total Fire Ban (TFB) days, ACRs are remotely set to operate at higher fault detection sensitivities and if a fault is detected, power will be turned off. This is to help prevent fire starts from fallen powerlines.
Covered conductors
These are overhead lines which have an insulated covering around them. They are being rolled out in targeted high bushfire risk areas where powerlines can also be affected by extreme weather like strong winds, salt spray, moisture or frost. By protecting powerlines, the covers also help reduce the likelihood of faults and fires.
Vegetation management
We are required to make sure the area around powerlines is clear and safe. Branches falling or flying loose in strong winds can bring down powerlines and cause power outages or grass fires.
We regularly inspect vegetation around our poles and wires and cut it back if necessary in line with regulated clearance distances. Councils are responsible for maintaining tree clearances in some urban areas.
Explore another page