water meter

ESA Warns of Electrical Hazards When Replacing Metal Water Meters & Water supply lines

Always assume there is a flow of electricity in the piping system. Workers should treat metallic water pipes as if they are energized.

ESA is warning on potential electrical hazards associated with the replacement of metallic water meters and water supply lines to plumbers. Any workers who undertake the replacement of a metallic water meter or metallic water piping system should be aware of a possibility of electrical shock or arcing occurring when the continuity of the water piping is interrupted. 

Workers must always assume that there may be flow of electricity in the piping system and deal with the metallic water pipes as if they are energized. A latent fault of a disconnected or deteriorated neutral connection in the electrical system will increase the risk, and removing a water meter or cutting the metallic piping system within or exterior to a building may cause an electric shock to the worker. An additional issue is related to the damage or interference with a metallic water pipe utilized as the ground electrode. When the metallic pipes are replaced with a non-metallic piping system, there is increased risk of fire where there are existing failures in the electrical system.

ESA recommends contacting a Licensed Electrical Contractor (LEC) to assess the condition of the existing electrical system including the neutral and grounding electrode connections. In some cases, arcing may be indicative of a more serious problem with the electrical system which requires investigation by an LEC. The Local Distribution Company (LDC) should be notified if the LEC has determined the arcing is from external sources.

Replacement of metallic water meters or repair of metallic piping systems 
An LEC may not be able to detect latent conditions in other premises or within the LDC’s infrastructure. For this reason, it is imperative that the continuity of the piping system be kept intact when cutting the metallic piping system or replacing a domestic water meter is carried out. The installation of a temporary jumper (minimum No. 6 AWG copper wire) with clamps made for the application across the water meter or between broken sections of metallic pipe would be adequate to ensure the continuity of the grounding electrode is maintained with this type of work.

Replacement of continuous metallic supply line with non-conductive water supply line
When replacing the metallic water supply line to non-conductive water supply line, a new ground electrode is required to be installed by an LEC prior to the existing piping/grounding electrode being removed. Connection to a grounding electrode is considered electrical work. A notification of work shall be filed with ESA.

For more information, please see: Flash Notice 20-26.

About the Electrical Safety Authority

The Electrical Safety Authority's (ESA’s) role is to enhance public electrical safety in Ontario. As an administrative authority acting on behalf of the Government of Ontario, ESA is responsible for administering specific regulations related to the Ontario Electrical Safety Code, the licensing of Electrical Contractors and Master Electricians, electricity distribution system safety, and electrical product safety. ESA works extensively with stakeholders throughout the province on education, training and promotion to foster electrical safety across the province.

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