AS/NZS 5033 has been at the heart of New Zealand and Australia’s solar sector, providing guidance on PV array installation, design, and maintenance. The 2021 revision completely rewrites the standard, increasing the maximum PV array voltage to 1000V from 600V. Moreover, it enhances safety requirements for DC isolators, cable management, and protection devices. The new standard enforces stringent rules for commissioning and maintenance to ensure long-term reliability. By increasing the voltage, it aligns local standards with international ones, thereby maximizing efficiency and cost-effectiveness in system design.

The 600V Restriction and the Role of AS/NZS 4777.1

Although AS/NZS 5033:2021 allowed 1000V systems, a conflicting requirement still existed. Specifically, the grid-interactive inverters standard AS/NZS 4777.1:2016 defined residential installation capacity as 600V. Consequently, this restriction prevented local installers from setting up high-voltage systems in residences, creating a regulatory challenge. Furthermore, the contradiction blocked the use of higher-voltage systems in domestic installations. However, AS/NZS 4777.1:2024 resolves this issue, now allowing solar PV domestic installations up to 1000V.

Benefits of the 1000V Standard

With AS/NZS 5033:2021 and AS/NZS 4777.1:2024 now aligned, local and commercial solar PV systems can fully benefit from the 1000V standard.

Higher system voltages reduce resistive cable losses, thus ensuring maximum energy efficiency. By minimizing parallel string applications, they simplify system design. In addition, transitioning to 1000V also lowers installation costs by reducing the number of required components such as cables and junction boxes. Simpler installations further cut labor costs. Moreover, relaxing the voltage restriction allows longer strings and improves space efficiency. As a result, residential and large commercial buildings can now be built more effectively. Aligning with global standards also strengthens the local industry’s competitiveness.

Compliance and Safety Considerations

The 1000V standard enhances compliance and safety.

AS/NZS 5033:2021 introduces new conditions for designers and installers. Therefore, they must now use DC circuit breakers, isolators, and fuses with higher voltage ratings. Additionally, cables require improved insulation and coverings to withstand arc faults and electrical shocks. Installers must also perform earthing and bonding correctly. Furthermore, they need to fully commission and test systems for compliance before energization. Proper documentation of all safety and performance tests ensures adherence to standards.

Industry Challenges and Adaptation

Although the shift to 1000V brings significant benefits, it also presents some challenges. For instance, installers must undergo new training to safely work with higher-voltage systems. Additionally, residential inverters that remain at 600V require replacement or retrofitting. Likewise, regulators must apply the new standards correctly to avoid misinterpretation and non-compliance. Nevertheless, by addressing these challenges, the sector can fully leverage the advantages of the 1000V regulation while maintaining safety standards.