Electrical Safety for Plumbers Working on Metallic Water and Gas Lines
Plumbers are at risk of serious or fatal electrical shock if they:
- Cut or disconnect a metallic water pipe;
- Disconnect a metallic hot water service;
- Remove a water meter;
- Disconnect the main Earth Wire from a water pipe;
- In some instances the above examples equally apply to Gas Lines; or
- Come into physical contact with a Water or Gas Line that has an electrical fault current present.
Plumbers can receive an electrical shock if there is a fault in the electrical supply system on the premises where they are working or in the street. Current can flow in the earth wire and onto the water piping system making it "live" - contact with a live system can cause serious of fatal electric shock.
You need to be aware that you can receive a fatal electric shock from a Metallic water service if you do not employ safe work methods. And if you employ others in your business, you are responsible for their occupational health and safety.
What to do if you are working on Water and/or Gas Lines?
You must employ safe work methods that YOU have validated. The following are some suggestions that you could consider in formulating best practices for yourself and your team when working on Water and/or Gas lines.
- Locate the main electrical switches on the premises and turn them off.
- Attach a "DANGER DO NOT SWITCH ON" tag or lock the switchboard to prevent operation until you have completed your work.
- Fit an approved bridging conductor to either side of the section of the pipe being cut and keep it in place until the work is complete. It is recommended that an insulated bridging conductor (bonding strap) be used - braided copper lead capable of carrying a minimum of 70 amps that has appropriate end clamps and insulated hand grips.
- Use a multimeter prior to commencing work to ensure that there is no electrical current present.
- Ensure that the surface of the pipe is clean and in good electrical contact with the clamps of the bridging conductor. The electrical bridging conductor must not be broken or removed until all work on the water service is complete and the continuity of the metallic service pipe is restored.
- It is recommended that you contact a licensed electrician if the main earth connection to the water pipe has to be disconnected. The electrician can make the necessary alterations to maintain a safe and effective earthing system.
- If a metallic water service is being replaced with a plastic water pipe, the alterations to the earthing system must also be made by a licensed electrician.
Furthermore, in developing your Safe Work Practices, you should also consider the following when working on metallic water or gas services:
- If you see arcs or experience tingles there may be a fault in the system. Report the incident to the local electrical network operator.
- Use a bridging conductor (bonding straps) whenever cutting out sections of metallic water or gas lines.
- Use insulated gloves.
- Use a safety switch to reduce the risk of shock from your portable tools.
- Call 1100 before you dig to find out if there are any underground cables.
- If you are required to work near the overhead electrical connection on the premises you may need to have the supply conductors disconnected by the power authority.
- If kneeling or lying down on the ground to perform works, use rubber insulating mats where applicable.
NOTE: The Water main and associated piping may still be "live" if an electricity supply fault occurs on the street side of the water meter and the water service is not plastic. In this instance, you cannot eliminate the risk of electric shock by isolating the electrical power at the premises. The primary risk control measure is to attach a bridging conductor.
There has already been at least one fatality due to electrocution - please ensure that you take every precaution needed to protect yourself and your workers.
A big thank you to Steve Nunn from Nunny's Plumbing for highlighting this important issue and supplying the detail for this article. Thanks Steve!