Safe use of portable generators | Resources Safety & Health Queensland Skip to content
Print notice
Bulletin Banner

Mineral Mines & Quarries Inspectorate | Bulletin | No.200 V 1 | 17 February 2022

Safe use of portable generators

What happened?

Incorrect use of portable generators caused by unsafe installation and operating practices have caused several high potential incidents in Queensland mines and quarries recently. These have included exploding batteries, fires and electric shocks.

How did it happen?

High starting currents in batteries have caused explosions. Electrical faults and leaking fuel or engine oil contacting hot exhaust components have caused fires. Damaged and burnt extension leads and fittings have caused electric shocks.

Key issues

  • Portable generators can be hazardous if the manufacturer's instructions are not followed.
  • Generators must always be used in a safe, dry, ventilated work area, away from fuels and flammable materials.
  • Damaged extension leads and power boards can be an electrocution hazard.
  • Hot engine components, sparking terminals, fuels and battery gases can be a fire or explosion hazard.
  • Back feeding into existing installations without a change-over switch can overload the generator and create electrocution hazards.


  • Use generators outside. Never use them indoors. Consider installing a carbon monoxide alarm in covered work areas.
  • Keep generators dry. Do not use them in the rain or in wet areas and protect by operating on a dry surface under an open roof. Ensure your hands are dry before touching generators.
  • Battery terminals must be shrouded and routinely checked to ensure they are tight. Battery covers must be secured in place before the generator is started.
  • Plugging appliances directly into the generator is the preferred connection method. Alternatively, use a heavy-duty outdoor-rated extension lead that is rated in watts or amps for the sum of the connected appliances. Consider metal braided leads and check that the entire extension lead is free of cuts or tears. Ensure that the plug has all three prongs, and these are not damaged or modified to fit a different size socket.
  • Store fuel for your generator in properly labelled non-glass safety containers. Fuel should be kept in an appropriate location and away from any ignition sources.
  • Before refuelling the generator, turn it off and let it cool down. Fuel spilt on hot engine parts can ignite.
  • Never try to power an electrical installation by plugging the generator into a power point.
  • Get a licensed electrician to install a change-over switch when connecting a generator to a grid powered electrical installation.
  • Follow the manufacturer’s instructions for the safe use of the generator.

The Mining and Quarrying Safety and Health Regulation 2017 requires that earth leakage protection is provided for each electrical circuit exceeding extra-low voltage (ELV) that has an outlet for, or supplies, electricity to a trailing cable or flexible lead. This requirement excludes the use of portable generators without residual current device (RCD) protection from being used as a power source for portable power tools and appliances in Queensland mines and quarries, unless the circuit is isolated from earth. A multiple earth neutral (MEN) link must be installed upstream of the RCD for the earth fault protection to be effective.

Additional safety measures are required to reduce the risk of simultaneous earth faults on isolated winding generators in heavy industrial and mining environments. Damage to electrical equipment and tools is likely to occur in these work environments.

Isolated winding generating sets with more than one outlet can be used, provided each generator does not supply more than one item of Class I (earthed conductive parts) electrical equipment at a time.

RCD protected generators with multiple socket outlets, with 30mA RCD protection, may be used to supply multiple items of equipment.


  • Consult a licenced electrician to determine if you have an isolated winding generator.
  • RCD protection is required unless it is an isolated winding generator.
  • If an isolated winding generator has two socket outlets, only one can be used at a time.

Authorised by Trevor Brown - Deputy Chief Inspector – Mineral Mines & Quarries

Contact: Graeme Trevorrow, Inspector of Mines , +61 7 3199 8001

Issued by Resources Safety & Health Queensland

Safety: This information is issued to promote safety through experience. It is not to be taken as a statement of law and must not be construed to waive or modify any legal obligation.
Placement: Place this announcement on noticeboards and ensure all relevant people in your organisation receive a copy, understand the content, findings and recommendations as applicable to their operation. SSEs should validate that recommendations have been implemented.