The recent death of a construction worker who was electrocuted when a metal shed frame contacted a high voltage overhead powerline has highlighted this often-overlooked risk which construction companies must address on site.
Initial enquiries indicate the frame was being moved onsite by a crane when the worker tried to stop it from striking a nearby vehicle. It was not known that the metal frame had made contact with an overhead powerline at the time. Investigations are continuing.
Issues of this nature in the past have prompted prosecutions for work safety breaches. Contact with overhead powerlines or even just coming too close to them can be fatal. Workers and the equipment they are using do not need to come in direct contact with them as electricity at high voltages can jump quite large gaps. All electric line voltages are lethal, with the risk of flashover increasing as the electric line voltage rises.
The most common electrical risks associated with working near overhead powerlines are:
- electric shock causing injury or death
- arcing, explosion or fire causing burns (arcing or explosion or both occur when high fault currents are present)
- fire causing property damage.
Hazards from overhead powerlines may arise from:
- something the person is holding, or is in contact with, coming too close to them
- operating plant such as a crane too close to them
- building structures close to them.
If an incident occurs, you'll need to show the regulator that you’ve used an effective risk management process. This responsibility is covered by your primary duty of care in the Electrical Safety Act 2002 and the Work Health and Safety Act 2011.
The Electrical Safety Act 2002 places duties on people to ensure electrical safety: persons conducting a business or undertaking, designers, manufacturers, importers, suppliers, installers, repairers, persons in control of electrical equipment, workers and others.
Effective control measures for working near overhead electric lines are often made up of a combination of controls. This includes eliminating the risk of electric shock by turning off the power. The PCBU, principal contractor or operating plant owner should discuss options for de-energising or re-routing the electricity supply with the relevant electricity entity.
De-energising or re-routing should be arranged with the electricity entity as soon as possible as it can take some time to arrange. Where overhead powerlines have been de-energised, confirmation should be sought from the person in control of the powerline before undertaking any work.
If eliminating the risk of contacting overhead powerlines by de-energising or re-routing is not reasonably practicable, you must consider using a combination of control measures.
If you must work near powerlines, you should follow these steps:
- develop a safe system of work before you start work
- avoid going into exclusion zones (within 3m for up to 132kV lines and 6m for up to 330kV lines) – remembering that powerlines sag or sway in hot or windy weather
- keep your workers and contractors informed about electrical safety.
Remember, the controls that are put in place to ensure electrical safety must be reviewed regularly to make sure they work effectively.
- Electrical Safety code of practice 2020 - Working near overhead and underground electric lines
- Working safely near powerlines in the construction industry
- Mobile crane code of practice 2006
- Ergon Energy
- Look up and Live map - displays the Energex and Ergon Energy electricity networks
- Exclusion zones
- Electrical exclusion zones - Film