Using back-up generators with Solar PV installations

The purpose of this Safety Alert is to highlight the requirement of having an integrated system with changeover switch to isolate the grid and Solar PV before using a back-up generator to power a house or business.

Background

Cyclone Marcus caused significant damage to essential services, resulting in widespread power outages for a number of days. Some households have been using generators to provide electricity while the power was being restored.

Electrical Safety Inspectors have attended households where back-up generators have been connected to systems with Solar PV which have not been properly integrated.

Running a back-up generator whilst the Solar PV is connected is not generally permitted. A generator is not designed to absorb energy from a solar inverter energy system (IES). Unless the system has been specifically designed, the IES is required to be disconnected to prevent a fire risk and serious damage to the generator.

Action required

• Households with a Solar PV installation who want to use generator back-up should check with their licenced electrician or accredited solar installer to:
• Install a Grid to Generator change-over switch to isolate the grid from generator.
• Ensure the Solar PV is connected to the grid side of the change-over switch unless specifically designed to operate in parallel or provided with a ‘Fail-Safe’ method of remote isolation.
• Ensure the ‘Fail-Safe’ method of remote isolation is used in accordance with ASNZS3000:2007 - 2.3.5.
• Ensure that a semiconductor (solid-state) device is not used for isolation purposes.

Further information

Legislation

• Electricity Reform (Safety and Technical) Regulations 2000

Australian Standards

• ASNZS 4777.1:2016 - 3.2.2 - Solar PV and Backup Generators
• ASNZS 3000:2007 - 2.3.5 Emergency switching including emergency stopping
• ASNZS 3000:2007 - 2.3.2.2 Devices for isolation