Are there any open source plug-in devices (or wire-in, or via CTs) that measure and log (to the s or ms or whatever) the voltage and frequency of a home's power?
It's 4am and I notice the incandescent lights periodically dim, even though no loads are clicking on inside the house (so, some kind of large load happening outside / brownout?).
Just curious when the dips are and if there’s any pattern. (and if I also measured my home's current too could also differentiate the cause of a voltage dip).
@colinstu You’re spot on about the importance of measuring both current and voltage (whenever possible) when you want to understand a power quality problem.
I’ve seen a couple of open source devices but they only appear to monitor voltage. (It’s better than nothing but often doesn’t provide a complete picture.)
Wonder if you have heavy manufacturing loads near you operating late at night (when electricity is much cheaper) like arc furnaces.
@colinstu I always warn people in case they aren’t aware - current transformers (CTs) are inherently hazardous because ideally they put out a constant current, and their voltage will skyrocket if the output (secondary) is open-circuited while current is flowing through the ring (the primary). Also can damage the CT.
Ones we had at work (1200:5) that could go as high as 7kV open circuited.
Smaller ones probably have lower open circuit voltages but still could be heart-stopping.
What you say is a perfectly valid warning about "component level" current transformers, and some professional handheld clamps
The "current transformers" for home automation that i see the recent years all seem to have integrated load resistors giving a voltage output that can be left open without any harm
@Laberpferd@colinstu Funny thing here - if you get a current sensor for your power panel, don’t put both of the incoming 120V lines through one sensor.
Because the waves are 180° apart, the signal measurements will cancel out except for the difference.
So if you have 100A on L1 and 75A on L2, you’ll ideally measure 25A. If they were both 100A, you’d measure nothing.
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