Durban in the dark over cause of huge outage
... but photos on social media hold strong evidence that neglect was the culprit
An explosion and fire at an eThekwini Municipality electrical substation – which resulted in citywide blackout on Wednesday – would probably not have happened if infrastructure had been maintained, if pictures circulating on social media are anything to go by.
Photographs of charred electrical hardware, posted by the municipality on their Facebook page to quell viral fake news, inadvertently provide critical insight into the potential cause of the fire.Energy expert Chris Yelland said that well-maintained and regularly monitored electrical infrastructure would not fail.
This is the second explosion at the city-run Klaarwater major substation in as many years, with a 2016 blaze also plunging the city into darkness.
Hospitals, business and other critical infrastructure relied on generator power for nearly three hours in a throwback to an era of load shedding.
He said that a fire, often a result of outdated and poorly maintained infrastructure, was an indictment of its upkeep.“A fire incident should never happen … not in a well-maintained and looked-after substation,” he said.
“You can see from the picture that the tank of what looks to be an electrical transformer has ruptured. That kind of equipment will generally contain transformer oil which, while combustible, is an insulating medium,” he explained.
“Many factors like poor maintenance, ingress of moisture, seals which are no longer functioning because they are old or poorly maintained can cause a rupture,” Yelland added.
He said that the presence of moisture, dust or other foreign particles causes “partial discharges”, small arcs which generate gas and a resultant pressure build-up over time.
“The final result is an insulation failure and a flash over from the high voltage components to the tank itself. It is like a short circuit inside the tank which causes rupture. The oil all spills out and the arc is a hot, fiery, arcing flame that causes the oil to ignite and it can sustain combustion,” he said.He said that often the fire then spreads to other substation components which also contain oil, with a knock-on effect.
“In many older substations, various items contain oil as an insulation fluid. In more modern ones they generally have non-combustible insulation fluid,” he said.
On Wednesday afternoon engineers were still scrambling to restore power to affected areas.
“An explosion at the 275kv Klaarwater major substation this morning caused widespread power outage to about 50% of areas in Durban,” the Municipality said in a statement.
“The City appeals for patience while we work around the clock to restore power in all affected areas.”