Before installing water meters or repairing or replacing metal water services, plumbers and their assistants should plan and use a safe system of work to prevent or minimise the risk of electric shock.
Under normal conditions, electricity that enters an electrical installation to power electrical equipment will return to the local substation transformer via the neutral conductor.
However, under certain fault conditions, metal water pipes may provide the return electrical path instead of the neutral conductor. Plumbers working on metal water pipes under these conditions are at risk of serious, even fatal, electric shock.
Working on metal water services
Before installing water meters or repairing or replacing metal water services, plumbers and their assistants should plan and use a safe system of workto prevent or minimise the risk of electric shock.
The safe system of work you use should suit the particular situation and should include the following procedures (refer to AS/NZS 3500.1 Plumbing and drainage Part 1: Water services).
- Plan the job by assessing electrical and other risks and taking suitable steps to stay safe.
- Where possible, switch off the electrical main switch, or switches, at the premises and attach a tag reading 'DANGER DO NOT SWITCH ON'.
- Take additional steps to reduce electrical risk. Your work methods should avoid skin contact with metallic water pipes being worked on e.g. gloves and long trousers.
- Thoroughly clean a section of metal pipe on each side of the length being repaired.
- Attach an insulated bridging conductor—stranded copper cable capable of carrying 70 amperes that has appropriate end clamps with insulated handgrips—to span the length of pipe to be cut.
- Check to ensure the clamps make good electrical contact with the metal pipe.
- Check to ensure the bridging conductor remains undisturbed until the work is finished.
- Where any existing metallic service pipe is to be replaced by non-metallic pipe or fittings, have the electrical installation checked by a licensed electrical contractor and modified if necessary to ensure the electrical earthing system for the premises remains effective.
- Notify the local electricity distributor and the householder immediately if you see anything abnormal such as electric sparks or you feel an electric shock.
Including these procedures in your safe system of work will reduce the risk of electrical incidents when installing water meters or repairing metal water services.
Check to ensure electrical equipment such as leads and power tools are safe to use and have them tested and tagged regularly.
Don't use any faulty or damaged electrical equipment. Replace it or have it checked and repaired by an appropriately licensed electrical worker.
Other safety tips
Before you dig
Always consult with your local providers of electricity, communications or other services before you dig. Visit Before You Dig Australia (BYDA).
Look up and live
Check the location of overhead powerlines before starting work. Exclusion zones specify the minimum safe distance from powerlines. Stay safe around powerlines by planning your work to ensure you stay outside the specified exclusion zones.
A safety observer could be a life saver – use one if there is a risk of coming too close to powerlines. If replacing guttering or doing other work at heights, stay away from powerlines.
If necessary, arrange for a licensed electrical contractor to temporarily disconnect (and later reconnect) the electricity supply to an installation, to allow you to work safely around an electrical service line.
Watch our electrical exclusion zones film for more information.
Safety switches save lives
Using a safety switch when operating electrical equipment will keep you and your workmates safer. Find out more about safety switches at www.electricalsafety.qld.gov.au