In August 2024, Standards Australia released a new version of AS/NZS 4777.1 Grid connection of energy systems via inverters Part 1: Installation requirements (AS/NZS 4777.1:2024).

The update saw a range of changes to improve the safety of electrical installations and support the security of the electricity supply network.

These changes will support the continued increase of solar photovoltaic (PV), batteries and electric vehicles.

Since 23 February 2025, it is mandatory for all inverters connected at low voltage to the distribution network to be compliant to AS/NZS 4777.2:2020 and installed in compliance with AS/NZS 4777.1:2024.

Some of the main changes and how these changes will be adopted by Distribution Networks Service Providers (DNSPs):

Change to protection requirements from ‘Central’ to ‘Interface’

A grid protection device is a device installed between the inverter energy system (IES), aka solar inverter, and the power grid to maintain safety and stability of the power grid.

The new standard removes the requirement for network protection under 200kVA. It means that system will be more cost effective and faster to install.

For systems above 200kVA, the interface protection will apply to IES or aggregate IES on electrical installation. This requirement is applied for all DNSPs in Australia.

Some variations may apply for interface protection limits and may be different for each DNSPs.

Introduction of phase balance limits

The other important change is the new phase balance limits. The standard now sets a limit of 30 kVA for single-phase installations.

For multi-phase IESs, requirements are different for IESs with aggregate rating of less than or equal 50 kVA and for IES with aggregate rating more than 50 kVA.

This update is crucial for larger installation, where higher capacities are common.

Introduction of new terminologies for supply types

The standard has introduced new terminology for the types of supplies associated with inverters to support safe installation and operation of inverters.

These supply types also assist in identifying when inverters are considered grid connected and are required to meet DNSP technical requirements, inverter compliance requirements and need approval from the DNSPs prior to connection.

There are four supply types described in the standard: supplement supply, alternative supply, substitute supply and independent supply.

The table below shows the basic compliance and approval requirements for each supply types. Noting that compliance and approval requirements may vary between DNSPs for the various supply types.

*Any inverter capable of substitute supply will be either a supplementary supply or an alternative supply which is normally grid-connection. Approval is required for connection of the inverter as either supplementary supply or alternative supply.

The standards also introduce new categories like inverter power sharing device (IPSD) and vehicle to grid (V2G) to ensuring consistency across related standards.

More info on how DNSPs will apply these new changes

All in all, these updates are intended to streamline the compliance process and support the growing use of renewable energy. It’s important for anyone involved in the design, installation, or regulation of solar and battery systems, whether for residential or commercial purposes, to be familiar with these changes.

For this reason, Energy Networks Australia has prepared Frequently Asked Questions (FAQ) to provide a high-level guidance on how DNSPs have adopted the new changes. The FAQ was published on 21 February 2025, available here.