Load-shedding blamed for arcing at Parkrand substation in Ekurhuleni

What happened

On 11 April 2023, residents of Parkrand, Ekurhuleni, were without power for several hours after an equipment failure at a substation in Plomer Street. Residents heard popping sounds, then saw a bright flash and heard a bang, which prompted the City of Ekurhuleni to send firefighters and technicians to the facility. Some residents said they had earlier seen a persistent orange glow from the equipment. The city said the substation was not on fire but that electrical arcing had occurred on the outdoor equipment, damaging high-voltage links.

Technicians restored power after discovering tampering with the electrical infrastructure; the source reports that this led to a brief interruption in supply. The cost of repairs had not been determined, and tests on associated distribution apparatus were planned to check for further damage.

Contributing factors

The City of Ekurhuleni attributed the fault to persistent load-shedding, stating that massive loads switched on and off on distribution networks are not designed for sustained load-shedding. Tampering with the electrical infrastructure was also found during restoration. No other contributing factors were reported.

Lessons learned

1. Sustained load-shedding repeatedly switches large loads on and off, which can stress distribution equipment beyond its design basis, so operators should assess switching limits and monitor equipment under such conditions.
2. Arcing on outdoor high-voltage links can produce flashes, bangs and visible glow that alarm the public, so thermographic and partial discharge checks should catch deterioration early.
3. Physical security of substations and their wiring needs regular inspection, since tampering can cause or compound faults and should be checked during any restoration.

More lessons on detection and monitoring, theft, arson and site security, from every incident on the register.

Source

citizen.co.za