In August 2021, three electrical apprentices received electric shocks.
The first incident involved a school-based electrical apprentice who received an electric shock and burns to her hands while replacing fluorescent lights with new LED lights. Initial enquiries indicate she was working under the supervision of a licensed electrical worker in an administration building.
The second incident involved a first-year electrical apprentice who received an electric shock while fault finding on air-conditioning equipment. Initial enquiries indicate he was assisting an electrical tradesman to commission air conditioning units and was working under the supervision of a licensed electrical worker.
The third incident involved a second-year electrical apprentice who received an electric shock to the back of her hand. Investigations indicate she was installing a PVC conduit for a new air-conditioning circuit when she contacted the bare end of the new conductors.
These findings are not confirmed and investigations are continuing into the exact cause of all incidents.
Managing electrical risks
The Electrical Safety Act 2002 places duties on people to ensure electrical safety including persons conducting a business or undertaking (PCBU), designers, manufacturers, importers, suppliers, installers, repairers, people in control of electrical equipment and workers.
The risks associated with electrical work must be controlled and the control measures clearly communicated to workers.
Common electrical risks:
- Electric shock by direct or indirect contact, ‘step-and-touch’ potentials, tracking through or across a medium, or by arcing, for example:
- contacting a live terminal within energised electrical equipment (direct contact)
- from the earthed enclosure of an air conditioning unit when an active earth fault occurs (indirect contact).
- Fire, arcing or explosion causing burns and injury.
- Toxic gases causing illness or death. Burning and arcing associated with electrical equipment may release various gases and contaminants.
Control measures to prevent similar incidents
Effective control measures for electric shock are often made up of a combination of controls. Under section 16 of the Electrical Safety Regulation 2013 (ES Regulation), a PCBU must ensure that electrical equipment has been de-energised to allow electrical work to be carried out on it is not inadvertently re-energised while the work is being conducted.
Section 17 of the ES Regulation requires licensed electrical workers to take precautions to prevent de-energised equipment from being inadvertently re-energised. They must ensure:
- a suitable warning sign under AS1319 (safety signs for the occupational environment) is attached to the device in a prominent position
- the device is locked when in an open position, for example:
- using a personal lock to lock an air-conditioner isolator in the open position
- using a locking device that stops a miniature circuit breaker from being closed
- placing a lockable shroud on the male inlet plug of electrical equipment
- the device is prevented from being accidentally closed, for example:
- disengaging a circuit breaker so that the circuit breaker is separated from the busbars
- removing circuit cables from the fuse or circuit breaker
- inserting a mechanical restriction.
Under section 279 of the ES Regulation, a PCBU who employs a ‘training person’ who has not finished six months of their apprenticeship or training must ensure they do not work:
- in the immediate vicinity of a live high voltage exposed part
- where there is a risk they could contact a live low voltage exposed part.
They must also ensure that a training person who performs electrical work, is always supervised by an electrical worker licensed to perform the work.
A supervising tradesperson must always be readily available to the apprentice. Whether this is in the immediate vicinity or contactable through other means such as phone, depends on the skill and competency level of the apprentice.
Apprentice supervisors must prove the equipment the apprentice is working on is not energised before the work starts.
When it comes to isolation of electricity, remember ABC:
- Assume nothing.
- Believe no one.
- Check everything.
Always test before you touch and never assume parts of electrical equipment are de-energised.