City gets mobile to keep the power on through winter

THE City of Joburg launched South Africa’s first mobile on-site testing of high-voltage power transformers at a Sandton substation last week.

In light of the city’s R69 billion backlog in development and maintenance of electricity infrastructure, it needs to be innovative to keep up with international trends, which have proved successful in addressing infrastructure failures, said Nico de Jager, member of the mayoral committee for environmental and infrastructure service delivery.

Maschinenfabrik Reinhausen South Africa recently bought a mobile high-voltage power transformer testing trailer, and partnered with City Power and Eskom to perform specialised tests on high-voltage power transformers.

City Power purchases electricity from Eskom at the Delta substation, which is then distributed to three large power transformers, which, in turn, supply many substations across the city.

As such, these power transformers are critical assets in City Power’s electrical network.

“Over the course of the past year, and to the inconvenience of many residents, City Power has experienced numerous power trips at one of these power transformers,” said De Jager.

To ensure that extended power outages become a thing of the past, City Power will retest this faulty power transformer with new technology rather than conventional testing methods, which have not yielded adequate results, he said.

Mobile on-site high-voltage tests on transformers are increasingly considered a necessity to carry out quick on-site repairs, running of diagnostics, installations and quality conformation.

The US, Australia, China and many European countries already use this technology.

This type of testing will ensure that downtime is reduced as repairs will be done speedily, ensuring residents don’t spend long periods of time without electricity, especially during the cold winter months, De Jager added.

Making use of mobile testing on-site will also enable City Power to make informed decisions about the repair of the power transformers based on proper diagnostic analysis and allow for possible repairs to be conducted on-site without having to transport the power transformer to a workshop.

“Due to the sheer size of the power transformers, and at a cost of about R35m each, it is extremely expensive and time-consuming to transport and ‘un-tank’ them in a workshop. In this regard, mobile on-site testing is also cost effective.”

Electrical insulation also ages over time, depending on its operating conditions, and it is essential for City Power to extend the remaining life cycle of this faulty transformer to at least another 40 years.

The city was committed not only to delivering the quality services that residents demanded and deserved, but also to set the standard for other metros and municipalities across the country in terms of innovation and finding long-term solutions to the country’s electricity woes, De Jager said.