Voltage Disturbance 22/02/2024 01:30

The PQUBE3 installed at my home’s incoming supply (230V Phase L3) detected an RVC (rapid voltage change) of 3.97% during the early morning of Thursday 22/02/2024.

And today, while retrieving a portable PQ monitor from one of our worksites in Banyan Drive, I noticed the following voltage trends (occurred at about the same time as my PQUBE3 event). This was recorded at 22kV.

For these 2 locations (one on the mainland in the western part of Singapore, and another on Jurong Island), to have similar voltage variations suggest that a transmission level fault had occurred during the said date/time.

We have two other sets of portable PQ monitors, one in Loyang (east of Singapore) and another in Marsiling (north of Singapore) which will be due for data retrieval next week. These PQ monitors would have similar stories to tell.

Updated – 28/2/2024

As expected, the other two set of portable PQ monitors captured the same event (at 22kV), with the PQ monitor at the northern part of Singapore saw the worst dip values, which was expected as the fault was made known to have originated from our northern neighbour (TNB – Malaysia).

22-02-2024 dip (east)
22-02-2024 dip north

Here, it can be deduced that it was a single-phase fault on the Blue phase (Phase L3).

Voltage Dip 3/2/2024 03:35

I had a PQUBE3 installed at my home’s incoming supply for about six months now and this was the first voltage dip (or sag) that it captured.

Apparently there was a transmission level cable fault in the Utility’s network. This would mean everyone in Singapore would have ‘seen’ it one way or another (in varying degrees, depending on locations).

My home (western part of Singapore) is taking in 230V single-phase supply (on Phase L3).

The PQUBE3 recorded a voltage dip of 18.44%, for a duration of 60ms (Lowest voltage was 187.6V).

Voltage Dip 03-02-24 0335hrs
Dip 03-02-2024 0335 Waveforms (Voltage & Current)

03022024 0335 dip rms
Dip 03-02-2024 0335 RMS Trend (Voltage)