Graph of mains voltage (Vrms) 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 This page's data starts from March 2023 at a new location - earlier measurements have been archived here (pre-21) and here (21-22)
Christmas Day
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: 26th April 2024
