Generator failure during load shedding cuts B feed at JSE data centre

What happened

At about 03:05 on 11 February 2024, the Johannesburg Stock Exchange (JSE) detected a power feed disruption at its colocation data centre in South Africa. According to the JSE service notice, the site was being load shed when a generator did not start. The batteries then depleted, which caused a power outage on the B leg power feed. Clients may have lost power to one of their dual-feed configurations for approximately 20 minutes.

The JSE said every rack has dual-feed power, so no customer should have experienced a complete power failure, but equipment with a single power supply connected to the B feed may have gone down. The notice listed equity, derivatives and colocation services as affected. The reason the generator did not start has not been reported.

Contributing factors

According to the JSE, the backup generator did not start when the site was load shed, and the batteries then depleted. Equipment with only a single power supply connected to the B feed was exposed to the outage. The JSE says every rack has dual-feed power. The full root cause has not yet been published.

Lessons learned

1. Test backup generators under load shedding or failover conditions, not only on a routine schedule, so that a failure to start is found before a real outage.
2. Size battery bridging time to cover the realistic time needed for a generator to start and take load, and alarm on battery depletion.
3. Require customers with single power supplies to be on a dual-fed path, and check that every feed remains independently supplied during maintenance or outages.

More lessons on outages, backup supply and restoration, detection and monitoring, from every incident on the register.

Source

clientportal.jse.co.za