CircuitSetup
commented
2 years ago Sorry for the late reply.
You can absolutely monitor voltage at 5 second intervals or less, as long as you have the ability to store the data. There are many users gathering data at 1 second intervals and storing in MySQL with EmonCMS or InfluxDB via Home Assistant.
CaptClaude
Maybe this answer is buried in the documentation somewhere but I haven't found it (yet). I am led to this project by my need to monitor my incoming voltage for sags & swells. I need to accumulate incoming voltage data to present to my utility to demonstrate that there is a loose neutral somewhere upstream of my meter (neighbor sees the same issue). Once I get that solved, I will be like the rest of your users and monitor my power consumption. I currently have borrowed Siemens 9630 power meter and record the RMS L-N voltage every 5 sec. To determine if the issue is load-dependent, I need CTs for the meter but there are no (affordable) split-core ones that can be used with the 9630 and I am not willing to pull the meter & disconnect the mains so I can install (affordable) CTs. This project looks like what I need (current and future) as long as I can sample/monitor line voltage and log min and max and potentially pull that data with Node-Red or push to InfluxDB and use Grafana. I'd like at least 5s reporting intervals, perhaps faster and I can average those samples elsewhere. I considered making a voltage monitor with an ESP32 and a bunch of AC-to-RMS chips but you've already done the heavy lifting and I should support that before re-inventing the wheel. The attached graphic is what I am seeing and it is not healthy for my appliances.