04/10/2026
Yesterday something unusual happened in the factory. After a scheduled outage on the 132kV feeder, power was restored about an hour later. Everything looked perfectly normal — voltage was stable, meter readings were fine, and there were no alarms.
A few minutes later, I received a message on the radio that all motors in the factory were running in the opposite direction while the rest couldn't even start. At first, it sounded strange, but after confirming, it was true. Every motor.. pumps, conveyors, everything. Has reversed. That was when it became clear that the phase sequence had been swapped somewhere upstream during maintenance.
We immediately contacted the substation, and they escalated it further. Not long after, an engineer from town came in to report that their pumps were also running in reverse. I explained that the issue wasn’t from our end but likely from the transmission side, possibly hundreds of kilometers away.
He still insisted on swapping the terminals on his feeder as a quick fix. I asked him what would happen if the transmission team corrected it while he had already swapped his. He said he would simply come back and swap it again.
Soon after, more ports started coming in from nearby towns Grinding machines and other equipment were all running in reverse, showing the issue was widespread.
For about three hours, the problem affected a large section of the 132kV line across the region before it was finally corrected and everything returned to normal.
It really makes you think. One simple phase reversal at the transmission level can affect an entire region. This is why phase sequence is not something to joke with in power systems.your all time systems industrial Engineer Duke
