6 February 2024
Western Power has issued the following advisory regarding the potential hazards associated with elevated neutral voltages:
Electric shocks or a tingling sensation from a water tap or electrical appliance can be a warning sign of a voltage rise in the earthing system, commonly resulting from broken wiring or loose, degraded connections, or an overloaded, unbalanced or poorly maintained electrical installation.
Electrical contractors are reminded that even with a Main Earth Neutral (MEN) connection scheme installed within the electrical installation, it is possible for the neutral conductor voltage to rise above the earth reference potential. Elevated neutral voltages can cause metal objects in and around a building to become live with dangerous levels of electricity. As neutral voltage increases, so does the risk of electric shock.
Neutral voltage rise can occur because of several factors, including but not limited to any or combination of the following:
1. connection of large single phase and or unbalanced multi-phase loads
2. connection of single-phase generation/renewable systems to multi-phase consumer electrical installations
3. high resistance or dysfunctional neutral connection(s) within a consumer’s electrical installation or at their connection point (MEN link)
4. undersize, long, high resistance or broken neutral conductors
5. high resistance or broken earth conductors
6. switching of neutral conductors (generation changeover devices)
7. high frequency harmonics, generated by power electronic devices.
These factors can generally be traced back to a consumer’s electrical installation.
Consumers have an ongoing responsibility, through their electrical contractor to ensure that their home or business remains electrically safe and fit for the purpose, which includes the consumer’s electrical installation connection to the network operator’s distribution network. Additionally, when connecting a new or altering an existing consumers electrical installation by increasing the site electrical load or installing/adding generation capacity, the consumer’s electrical contractor has an obligation to ensure that the requested electrical profile is balanced and protected in accordance with both regulatory and network requirements. Electrical contractors must carry out a new maximum demand calculation which reflects the circumstances of the new load or generation equipment. (AS/NZS 3000 clauses 1.6.3 and 2.2.2). The connection must also remain balanced where the connection is multi-phase, and in all cases be safe and compliant with current legislation industry standards and network operator requirements. This is particularly important when new loads such as high-current socket outlets, air conditioners, pool pumps, stoves, wall ovens, electric vehicle chargers and renewable energy systems are added to an existing residential and commercial installation.
Incidents of shocks and tingles need to be reported and fully investigated irrespective of their seriousness. As soon as practicable after an incident, call Western Power on 13 13 51 to report the nature of the electric shock or tingle.