ESA Warns of Electrical Hazards When Replacing Metal Water Meters and Water Supply Lines
The Electrical Safety Authority (ESA), an organization that enhances public electrical safety in the Canadian province of Ontario, recently issued a warning regarding potential electrical hazards associated with the replacement of metallic water meters and water supply lines to plumbers. According to the press release, any workers who undertake the replacement of a metallic water meter or metallic water piping system should be aware of the possibility of electric shock or arcing 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, advises ESA. 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. The organization also brought up an additional issue 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 that requires investigation by an electrical contractor. 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 electrical contractor 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, read this notice from ESA.