Construction wiring is the term used for temporary electrical installations on construction sites that supply power to and around the premise. While the wiring may be temporary, the installation requirements are not, and electrical workers must ensure construction wiring complies with the Wiring Rules, AS/NZS 3000, and AS/NZS 3012 Electrical Installations – Construction and Demolition sites.
Construction wiring is normally intended to be removed at the completion of the work, should not form part of the permanent electrical installation and needs to be clearly marked. We regularly audit construction projects to monitor construction wiring compliance. These audits have identified four main areas of concern.
- Electrical workers installing non-compliant construction wiring
If you are an electrical worker installing construction wiring you must ensure the installation is compliant to the Wiring Rules and the additional requirements of AS/NZS 3012. All construction wiring, including switchboards, fixed RCDs, emergency evacuation lighting and transportable structures, must be inspected and tested in accordance with the Wiring Rules following installation.
- Principal contractors or PCBUs failing to maintain the construction wiring installation
Our inspectors have identified construction wiring installations that have not been maintained or have been damaged during construction activities. The principal contractor on a construction site must ensure the construction wiring installed onsite remains compliant with AS/NZS 3012 for the duration of the project.
As a minimum the principal contractor must ensure construction wiring (including switchboards) is visually inspected every six months to verify the integrity of the installation. Where the visual inspection identifies damage or non-compliance to the standard, that part of the installation must be isolated, repaired or replaced, and tested as required.
- Failure to conduct risk assessments prior to installing construction wiring
Our inspectors have also identified installations that do not have adequate mechanical protection, particularly on temporary fences and transportable structures.
Electrical workers should conduct a risk assessment before installing construction wiring to consider the likelihood of the cables being subject to mechanical damage during any construction activities. If there is a risk of damage, the electrical worker must either consider relocating the cables or installing additional mechanical protection.
- Non-compliant switchboards are being installed in construction wiring installations
Our inspectors have identified switchboards that have been built by electrical contractors or PCBUs which do not meet the requirements of AS/NZS 3012. This standard details the specific requirements for switchboards installed as part of the construction wiring installation.
These include protection from mechanical damage, suitability for the environmental conditions and provisions for the retention of extension leads. We are particularly concerned about the methods used to install cables into these switchboards. Cables entering switchboards must be effectively secured in place to prevent mechanical damage.
Construction sites are dynamic workplaces with different trades and multiple activities occurring daily. All workers on site should be aware of the location of construction wiring and ensure the work being undertaken does not damage the installation. If you spot any damage to construction wiring you should report it to the site supervisor immediately.
Our inspectors will continue to audit construction wiring installations and take enforcement action if non-compliance is identified.