Over the past 6 hours, we've seen multiple drops in voltage due to the weather here - it has been raining on and off and there is thunder and lightning in the area. Attached plot shows what H0:FMC-EX_MAINS_CHAN_{1,2,3}_VOLTAGE are seeing.
Between 14:55-16:47UTC especially the voltage drops are quite large. Tagging DetChar
The last of these voltage glitches seen in the EX_MAINS voltage channels was at 18:46UTC.
We've had a lot of big drops in our range today, so I plotted the range against the EX MAINS voltage channels to see if there was any correlation between the glitches and the drops in range.
Highlighting the two hour time period on the voltage channels with the largest and most frequent drops in voltage (attachment1) shows that the range did start dropping more often around this time, but the large range drops still continued past this time. Some of the voltage drops generally line up with drops in the range in the following minute, but there is no consistant correlation. Attachments 2, 3, and 4 show the range channel overlayed on the voltage channels over the period of 12:00UTC to 18:00UTC. Attachments 5, 6, and 7 are zoomed in looks at the potential range drop following a power glitch. Notice that in some cases, another voltage glitch occurred a bit before but did not result in a drop in the detector's range.