Condition monitoring firm WearCheck has received accreditation from the South African National Accreditation System (SANAS) to perform dissolved gas analysis (DGA) at its Johannesburg-based transformer oil testing laboratory. The facility now holds ISO/IEC 17025 accreditation for a range of transformer oil tests including DGA, moisture, acidity, dielectric strength and polychlorinated biphenyls. It is the first privately owned laboratory in South Africa to earn this accreditation, according to Gert Nel, Transformer Manager at WearCheck.
DGA is a diagnostic tool used to detect internal faults in transformers by analysing gases dissolved in the insulating oil, says Nel. “Accurate gas analysis can help identify problems such as overheating, arcing or insulation degradation before they result in costly failures. Small amounts of gas are formed in the oil during normal operation but elevated levels of certain gases can indicate specific fault types.”
For example, oil overheating is associated with ethane and ethylene while insulation paper degradation produces carbon monoxide and carbon dioxide. Other indicators include hydrogen for partial discharge and acetylene for arcing faults.
Transformers are critical infrastructure assets and early detection of faults is essential for operational continuity, Nel says. “DGA enables remedial action to be taken before major damage occurs, helping to extend equipment life and avoid service disruptions.”
