Isolation of solar from backup generators

Generators must be isolated from the power network and from solar PV to avoid risks to persons and damage to the generator.

Many homeowners in the Darwin and the surrounding regions have a generator to support their electrical requirements during a power outage.

During a power outage, a generator connected correctly to the premises can be a valuable resource for the maintenance of critical equipment and necessary resources during a power loss or blackout.

A generator that is not connected correctly presents a significant risk to safety and equipment.

  • The power network must be isolated from the generator to prevent electricity being distributed into the public grid causing electrocution of anyone working on the supply lines.
  • Solar PV and other renewable energy sources are also required to be isolated from the generator to prevent damage to the generator and subsequent risk of injury to persons present.

The isolation and disconnections identified above are required to be automatically enabled in a manner that is safe if a failure or error occurs, i.e. “Fail Safe”.

  • Trying to rely on labels and instructions to isolate the solar PV before connecting the generator is of little use when faced by the difficulties caused by a loss of power.
  • Risks of failure are increased when the procedure is attempted to be used by persons that are not trained and practised in the process.
  • Not complying with these regulations can result in dangerous or non-compliant installations which are subject to significant penalties.

How to comply

  • A Northern Territory licensed Electrical Contractor is required to undertake the installation of the components that are required to perform the isolation and to ensure that all connections are correctly installed to protect your safety and your equipment.
  • The owner/occupier of the installation is required to receive an Electrical Certificate of Compliance as their warranty that the installation is correctly installed and meets all required standards.

Further information

For further information please refer to the following:


Locating a licensed electrical contractor:

Contact the Electrical Workers and Contractors Licensing Board


AS/NZS3000:2018 General

An inverter or regenerative supply source shall not be connected downstream of the generating set changeover device.

AS/NZS3000:2018 - Switching

The changeover device for an alternative supply shall be selected to maintain the function of, and prevent damage to, the electrical installation being supplied.

AS/NZS4777.1:2016 - 3.2.2 Connection to switchboard

Where an a.c. generating set is installed for purposes of an alternative supply system, an IES (Inverter) shall be connected to the grid side of any generator changeover device in the electrical