Charity’s roundtable seeks pen risk reduction

  Posted by: electrical-poster      13th April 2017

Electrical Safety First’s recent electrical installation safety roundtable focused on open-circuit PEN conductors, which act as both a protective earthing and neutral conductor.

Although PEN conductors within installations have been prohibited for some time now, older ones still remain in, for example, the rising mains in blocks of flats and military camps. When the PEN conductor fails, the diverted neutral current can not only present a shock hazard but can also create a significant heat build-up, as it typically makes a circuit via exposed metalwork (such as gas water and oil pipes, etc) – which can then lead to fire.

Data obtained from the Health and Safety Executive shows at least one incident of an open-circuit PEN conductor is reported every day – with around 10% of them leading to injury. But as many incidents go unreported, it’s believed the real figure could be significantly higher.

“Anecdotal evidence suggests that open-circuit PEN conductors might be a growing problem due to a range of factors – including our aging distribution system, metallic service pipes being replaced with non-metallic (alkathene) and the theft of copper from cables”, explains Martyn Allen, technical director at Electrical Safety First.

“The Charity is committed to promoting collaborative working and, while electrical distributors are legally required to ensure the safety of the electrical network, we believe that the electrical installation sector can also help reduce the risk legacy that open-circuit conductors can present.”

Among the key outcomes of the roundtable was a decision to establish a standard set of questions relating to broken PEN conductors, for use by trade and registration bodies when canvassing their members.

The opportunity to help mitigate the risk has also been recognized and considered by the Committees responsible for developing the 18th Edition of the IET Wiring Regulations. Requirements for foundation earthing, supplementary earth electrodes and over-voltage detection/protection devices, could be included in the draft for public comment on BS 7671:2018.

This is expected to be available from June – August 2017 and is accessible through the BSI Draft Review Portal at https//:standardsdevelopment.bsigroup.com.