The development of a remote temperature logging system for pole mounted distribution transformers
South African power utility company, ESKOM’s fleet of reticulation transformers is greater than 200,000. More than 90% of which are pole mounted transformers (PMT). In the winter months (May to September) the average PMT failure event is 2200. This costs the company R70.4Million ($4.1Million) annually. Additionally, this has a significantly negative impact (>10%) on system average interruption duration index (SAIDI). PMT failure events during the winter period are predominantly due to overloading therefore a remote temperature logging (RTL) system was developed to detect the overload condition and alert field services to upgrade the PMT before failure. The system is made up of 2 parts: the solar powered, temperature sensing devices with remote communication and a custom master station software. Using this system, it is now possible to predict the failure of PMTs (due to overloading) months before it happens, allowing enough time for replacement with a suitably sized PMT.