AMO members may find the recent Neutral Current Diversion Demonstration a valuable reminder of the risks associated with diverted neutral currents and broken PEN (Protective Earth and Neutral) conductors within PME networks. The demonstration uses a practical test rig to show how electrical current can continue to flow through unintended paths when a neutral conductor is compromised, creating potentially dangerous situations for both operatives and consumers.
The video illustrates how neighbouring properties can become electrically connected through shared metallic services and bonding arrangements. When a service neutral is interrupted, current may seek alternative return paths through gas pipes, water pipes and other metallic infrastructure, resulting in what is known as Neutral Current Diversion (NCD). The demonstration highlights that a property may continue to appear energised even when a neutral connection has been broken, potentially giving a false impression that the installation is safe to work on.
For metering professionals, the key message is that traditional isolation and proving procedures may not always identify the presence of diverted neutral currents. The demonstration reinforces the importance of following established safety processes, understanding the characteristics of PME systems, and remaining alert to circumstances where current may be flowing through extraneous conductive parts.
The wider industry continues to highlight NCD as an important safety issue. Research coordinated through industry bodies has shown that when a PEN conductor is lost or deteriorates, current can be diverted through shared metallic services, creating risks including overheating of bonding conductors, damage to equipment, elevated touch voltages, and in extreme circumstances fire or explosion.
The demonstration is particularly relevant to AMO members undertaking meter exchanges, service alterations, investigations and other work at customers’ premises. It provides a visual explanation of why operatives should never assume that disconnected conductors are free from current and why robust testing procedures remain critical when working on or around electrical installations.
Key Takeaways for AMO Members
- Neutral Current Diversion can occur when a PEN conductor is broken or compromised.
- Current may continue to flow through gas pipes, water pipes and other metallic pathways.
- A property can remain energised through alternative current paths even when the intended neutral connection has been disconnected.
- Operatives should remain vigilant and follow approved testing and isolation procedures at all times.
- Understanding the risks associated with PME systems and broken PEN conductors is essential for protecting both field staff and consumers.
AMO encourages members to watch the demonstration and share the key learning points with operational teams through safety briefings, toolbox talks and wider awareness initiatives. While Neutral Current Diversion (NCD) has traditionally been associated with metering activities, the risks are increasingly relevant across the installation and maintenance of low-carbon technologies, including electric vehicle charge points, solar PV systems, heat pumps and battery storage solutions. The video provides an important reminder that understanding and recognising NCD hazards can help prevent serious incidents, support safer working practices and raise awareness across the wider energy and low-carbon sectors—not just within metering.