This alert warns plumbers and other workers that fatal electric shocks can occur when removing water meters, or when cutting through or disconnecting metal water pipes.
Background
In October 2016, a worker in Queensland suffered a fatal electric shock while cutting a metal water pipe to repair a leak. Two similar incidents have occurred in NSW since 2005.
These types of incidents are usually caused by a fault in the electricity supply on the premises or in the street which causes the metal pipes to become 'live'. When the pipe is cut or disconnected the worker can get a serious or fatal electric shock.
Controls
Before removing water meters, or replacing metal water pipes, ask the customer about the operational condition of the electrical installation - if they have experienced a 'tingling' sensation after touching the pipes, taps or appliances:
- don't start work; tell the customer and electricity distributor you suspect a fault
- turn off the power, attach a danger tag - or lock the switchboard -and ensure the power remains off until the fault is fixed.
Even when the electrical installation appears to be in good condition, you should:
- use low voltage, insulated gloves when working
- clean the pipe each side of the length to be cut or disconnected - or either side of the water meter if the meter is to be removed
- attach a bridging conductor with a current rating of 70 amperes or greater. Ensure the clamps have good contact and don't remove the bridging until all work is completed.
- have the earthing requirements checked by an electrical contractor - and modified if necessary - if you're replacing the metal pipe with plastic or other fittings
- ensure you don't disconnect earth wires that may be attached to the metal water pipes. If it needs to be disconnected, or is damaged, the customer should get an electrical contractor to carry out the work.
More information
- Section 5.2 of AS/NZS 3500.1 Plumbing and draining - Water service deals with the installation of water services.
- Electrical safety for plumbers outlines more safety recommendations when working on water pipes.