Canberra’s electricity network is reliable; however, outages can still be caused by tree branches, weather, damage by third parties, animals, or equipment failure.
To respond quickly to any outages, we have crews on call to locate and repair faults on both the above-ground and underground electricity network. It also helps us detect faults when you call us to let us know the power is off or report any damage you see.
Our priority when repairing the network is always safety, followed by getting power restored as quickly as we can. If you see our crews on your street, we ask you please give them space and stay a safe distance away from any energy assets.
Underground fault detection
Our network has smart devices embedded in some areas that can detect and report underground cable faults immediately. However, most faults are identified when customers report a power outage to us by calling us.
Our fault-finding equipment is in a purpose-built van, and crews use various methods to identify the exact location of the fault and isolate it, including insulation resistance tests, sheath tests, and surging. When the affected cable is identified, crews disconnect it from the network. A continuity test checks that both ends of the cable have been positively identified as the correct cable which needs repair.
Once the fault is made safe, supply can generally be restored to most affected customers via alternate supply points and we can make repairs. To prevent future faults, we also look for issues such as old joints, tight bends, locations where cables run near tree roots or building works.
An example of an underground fault, where a cable has been damaged.
Overhead fault detection
Smart devices embedded within key components of our overhead network will detect faults and switch off the power. If there is not a visible issue, such as a tree on powerlines, we will use sectionalising to locate the fault by switching the power on and off. You may experience this if your power turns on and off again after an initial outage.
After isolating the affected area, crews asses the damage and make repairs ranging from minor fixes to complete replacement of powerlines and poles. The extent of the damage and other factors like weather conditions will determine how quickly we can restore power.
An example of an overhead fault, where a tree has fallen on powerlines.