Graph of mains voltage (V_rms) and frequency (Hz) over one week at Elmac Services

Description

This graph shows the mains frequency and voltage, recorded every 2 seconds and averaged over a 10 minute period throughout the day. The main line shows the actual average while the shading shows the spread of maximum and minimum values recorded during the 10 minute period. The monitoring location changed in April 2022. Select the location and dates to view from the box below, and hover the mouse over the graph to see the actual values at any given time. The graph can be zoomed by dragging within it, but to unzoom you will need to refresh the page and date. This page's data starts from March 2023 at a new location - earlier measurements have been archived here (pre-21) and here (21-22)

2023

Select week date (Monday - Sunday) to display

2024

Week January 1st Week January 8th Week January 15th Week January 22nd Week January 29th Week February 5th Week February 12th Week February 19th Week February 26th Week March 4th Week March 11th Week March 18th Week March 25th Week April 1st Week April 8th Week April 15th Week April 22nd Week April 29th Week May 6th Week May 13th Week May 20th Week May 27th Week June 3rd Week June 10th Week June 17th Week June 24th Week July 1st Week July 8th Week July 15th Week July 22nd Week July 29th Week March 13th Week March 20th Week March 27th Week April 3rd Week April 10th Week April 17th Week April 24th Week May 15th Week May 22nd Week May 29th Week June 5th Week June 12th Week June 19th Week June 26th Week July 3rd Week July 17th Week July 24th Week July 31st Week August 7th Week August 14th Week August 21st Week August 28th Week September 11th Week September 18th Week September 25th Week October 2nd Week October 9th Week October 23rd Week October 30th Week November 6th Week November 13th Week November 20th Week November 27th Week December 4th Week December 11th Week December 18th Week December 25th

Graphing courtesy of Dygraphs

Commentary

A description of the measurement system used for these graphs,  and some comments on the issue of mains frequency which triggered this project, can be found here. And recorded frequency excursions  outside the ±0.2Hz limits since late 2023 are shown here.

Last updated: 5th August 2024

• Discussion
• Excursions

NOTE: the weekly graphs have been paused for now (after the beginning of August 2024). If this causes problems, let me know and I'll see if I can restart them