Failures of cable and wire products are occurring regularly across South Africa, from household installations to critical generation, transmission and distribution infrastructure. According to Andre Smith, CEO of JSE-listed South Ocean Electric Cable (SOEW), one of the largest manufacturers and distributors of low voltage electrical wire, cable and accessories, the main causes are products that do not comply with specifications and the use of inferior materials.
“Non-compliance against specification typically involves issues with the type and quality of conductor measured by conductor resistance, insufficient radial thickness of the extrudate and incorrect lay length.
“Inferior materials being used include recycled metals or cladded metals with reduced current-carrying capacity, or insulation material not suited to the environment and failing environmental stress crack resistance.”
He says there is often a lack of metal deactivators in insulation materials or inadequate, lack of or inferior ultraviolet stabilisers such as carbon black, and poor or inadequate dispersion of these essential additives in the extrudate.
“Another frequent cause of failure is exceeding the minimum bending radius. This occurs when cables are wound onto a drum with a reduced belly diameter, either after rewinding onto a different drum by a wholesaler, distributor or contractor, or by an original equipment manufacturer trying to maximise space in a container for import purposes.
“Exceeding the bending radius severely damages cable integrity, harming insulation and creating air gaps between the conductor and insulation leading to an eventual breakdown.
“Some cables fail during commissioning and testing, others immediately after energisation, while some may operate for a period before failure occurs. Failure results in unwanted downtime, costly fault-finding and repairs.”
He adds that another issue is that with imported products, the original equipment manufacturer is often difficult to reach, warranties may not be honoured, and replacement stock is frequently unavailable locally at the time of failure.
To avoid these risks, Smith advises purchasing from a reputable local manufacturer with sound guarantees in place. “Because SOEW maintains a fully compliant test laboratory capable of testing from raw material through to finished product, including ageing tests, SOEW is able to provide the necessary guarantees, backed by a 35-year history in the South African cable sector.”