Source: Radio New Zealand
The change was introduced in 2025. (File photo) Supplied / New Zealand Electrical Inspectors Association
An independent review says a decision to change electrical wiring rules condemned by some as deadly, is justified but leaves residual risks.
Worksafe said this confirmed it was on a sound footing but the Electrical Inspectors Association was not buying it.
The changes lifted a total ban on inserting a switch, circuit or fuse into mains power earthing systems, known as protective earth neutral conductor (PEN) switching.
Worksafe ordered the review when the inspectors and others in the industry called on the government to intervene, saying it raised the risk of electrocution for households and businesses and it was out of step internationally.
It said it made the changes to future proof power networks for new technology that better enables charging electric vehicles, battery storage and homes generating solar power.
“The report concludes that the decision is justified, but that there are residual risks,” the 37-page review by a UK engineer said.
“Some of the residual risks are already mitigated by existing practices, standards and guidance, whilst others require additional industry guidance and/or standards to be implemented.”
It outlined five risks – a key one was where the protective conductor was switched so that “hazardous touch voltages exist without faults being present”.
Worksafe said the review confirmed its evidence-led approach to electrical safety regulation to future-proof the systems.
It advised against installing switches until it published extra advice.
But the inspectors association said the review should have been done by someone familiar with New Zealand’s system, that differed from the UK’s.
It pointed to the report itself stating, “It is not desirable to switch a PEN conductor under any circumstances. Not all countries enable switching of protective conductors in their national wiring codes. The UK is one country that does, but even in the UK, switching of PEN conductors is precluded.”
The association added, “The independent advice did not undertake any risk assessment/scoring, discuss risk controls or event directly analyse WorkSafe’s advice to MBIE.”
Worksafe said this type of switching had been allowed in some circumstances for decades and the “risks are well understood and can be managed through existing controls and other guidance”.
“Overall, the review confirms the advice supports innovation, energy resilience, and safety, consistent with Energy Safety’s role as the electricity and gas regulator.”
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
