Safe installation of construction wiring
April 29, 2019
Temporary power installations on construction sites intended to supply power to and around the premise are termed “construction wiring”. They are temporary and are to be removed at the completion of the work and should not form part of the permanent electrical installation and need to be clearly marked.
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.
Electrical Safety Queensland’s regular audit of construction projects to monitor construction wiring compliance has identified the following four main areas of concern:
- Electrical workers installing non-compliant construction wiring
The installation must be 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
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. Electrical Safety Queensland inspectors frequently identify construction wiring installations that have not been maintained or have been damaged during construction activities.
As a minimum, the principal contractor must ensure the 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
Electrical workers should conduct a risk assessment before installing construction wiring to consider the likelihood of the cables being subject to damage during any construction activities. Electrical Safety Queensland inspectors regularly find installations that do not have adequate mechanical protection, particularly on temporary fences and transportable structures.
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
Electrical Safety Queensland inspectors often see unacceptable methods used to install cables into switchboards which is of significant concern. Cables entering switchboards must be effectively secured in place to prevent damage. Electrical Safety Queensland 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 damage, suitability for the environmental conditions and provisions for the retention of extension leads.
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 any 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.
Electrical Safety Queensland inspectors will commence enforcement action if non-compliance is identified with any of the abovementioned issues.