Earlier this evening, there was a voltage dip that occurred just before 7pm. The following is a waveform captured at Low Voltage (monitored at L-N), located in the city area.
Reports of voltage dips from other PQ monitors in other transmission blocks suggest this was a Transmission-level fault.
Voltage waveform seen here was at LV (L-N). It mirrored what was seen at 22kV and above (at L-L). From here, it can be inferred that there was a transmission level single phase fault (Phase L1).