Long Voltage Sag in San Francisco Bay Area

Voltage Sag Cover Jan. 13th, 2021

Voltage Sag in San Francisco Bay Area

Wednesday, January 13th, 2021 at 6:46:37 AM – Most of the San Francisco Bay area experienced a long duration voltage sag this morning. For instance, in this most recent Power Quality event, the grid voltage sagged to 77% of normal for 47.16 cycles, or about 1/2 of a second.

A voltage sag of this magnitude lasting half a second is very unusual. The last time APT recorded an event like this there was an accident where the utility energized a new transformer with the grounds still applied. No root cause has been reported at this time.

Meanwhile, APT’s RECIPE Analytics software captured the incident and plotted the event on the ITIC acceptance curve as shown below.

RECIPE Analytics Power Quality Report for voltage sag Jan. 13th, 2021

Power Quality Event Investigation and Root Cause Analysis

Incidents like this often impacts your facility operation and costs time and money.

View Real-Time Quality of Service from your Utility:

  • Event Logs (Date, Time, and Duration)
  • Magnitude in either absolute voltage or a percentage of normal
  • Associated current inrush when voltage changes signficantly

No other quality of service solution shows the whole picture of your facility’s utility service. Moreover, preparing your facility with additional Power Quality Meters and an Electrical Power Monitoring System (EPMS) allows you to act on real-time data.

Voltage Sag detected Jan. 13th, 2021

APT provides solutions to identify failures like this as they happen.

Above all, we notify people who need to know faster and with better information – reducing or avoiding impact. A Power Quality Event (PQ Event) can occur anytime.

Things to Think About

  • Do you have a solution for capturing quality of service?
  • Did this event impact your operations?

For future updates and notifications on the latest power quality events, subscribe to the APT blog.

Brian Curnutt, Service Manager APT