Broadspectrum (now Ventia) has been part of the power industry in New Zealand for more than 60 years and is one of the country's largest electrical and communication services contractors.  

Broadspectrum provides end-to-end solutions to the power industry in transmission, distribution and generation through our extensive capability and innovative approach across New Zealand and Australia. 

Its Oil Laboratory team has been servicing New Zealand's high voltage and distribution electrical industry since 1987, specialising in the testing and analysis of insulating oils associated with high voltage electrical equipment.  

Insulating oils used in transformers, circuit breakers and high voltage bushings require appropriate and regular testing to monitor their condition and assess maintenance requirements. 

Inside the steel transformers that are connected to the electrical grid, transformer oil is circulated through radiator fins to get rid of excess heat into the surrounding air. Transformer oil, a type of insulating and cooling oil, needs to be tested periodically to ensure that it is still fit for purpose because it will naturally deteriorate over time. Moisture is one of the most common causes of deterioration in the insulating quality of the oil. A less rapid degradation process is the formation of acids and sludge, caused by oxidation. 

The rate of oxidation depends on the temperature of the oil - the higher the temperature, the faster the oxidative breakdown. Some electrical or thermal breakdown products are gaseous which are indicators of developing faults. 

Cellulous (or paper) degradation is another aspect that can be monitored through routine oil testing. Results obtained through Furans testing can be converted with the use of known conversion tables to predict the remaining life of a transformer.  This is a non-intrusive and simple way to understand the properties of other insulating components within a transformer.    

Broadspectrum offers comprehensive insulation oil testing and related diagnostic services in our own facility, providing our clients with the necessary information to safely and economically manage their electrical plant, ensure its reliability, plan necessary maintenance and predict when to replace equipment. 

Our IANZ accredited oil laboratory tests for transformer oil purity, quality and chemical composition using a range of industry-recognised oil analysis testing procedures. We offer a 5-10 working day service on small volumes, 11-20 working days on medium to high volumes and a priority rapid response service.  

For safety, continuity of service, efficiency and low-cost maintenance it is beneficial to regularly monitor the condition of transformer oil so that preventative action can be taken before equipment fails. The cost of testing and remedial maintenance is generally small in comparison with an unplanned, in-service equipment failure.