Fire destroys transformer at Lenasia South substation

What happened

A fire broke out at the 88/11 kV substation that supplies Lenasia South, South Africa. The article, dated 4 November 2022, reports that the fire started early that Friday morning. It is understood that this was immediately after, or during, restoration of supply following load shedding. City Power said the fire had been extinguished. It completely destroyed transformer no. 3, partly damaged the standby transformer, and burnt low-voltage cables and high-voltage line links.

City Power teams and a contractor were assessing repairs. Ennerdale and Hopefield substations, affected upstream, had been restored. Lunar substation was expected to be restored later that afternoon. For Lenasia South, City Power hoped to restore supply on Sunday evening if the standby transformer could be brought online, or on Friday 11 November if a replacement transformer had to be installed.

Contributing factors

The cause was not reported. It was understood that the fire started immediately after, or during, restoration following load shedding. No confirmed link between that timing and the fire was given.

Lessons learned

1. A substation fire can destroy a transformer and associated cables, so restoration plans should include a tested standby path.
2. Where upstream sites are also affected, restore those that can be returned first so the outage is not wider than necessary.
3. Replacement transformers, oil, terminations and commissioning tests can push restoration out by several days, so materials and test time should be planned for.

Source

citizen.co.za