Open energy monitor is both a commercial product and open source hardware/software, they have pages on using ct clamps. https://learn.openenergymonitor.org/electricity-monitoring/ct-sensors/introduction There is also a commercial product that uses 2 ct clamps and technology derived from speech recognition to analyze the powrer signal to detect what devices are running and even when appliances are gettimg ready to fail. I'd probably own one of these, but I am allergic to clouds.