Do these need to be installed inside the panel, or would it be possible to measure power on, for example, a mini split by clamping these around the wire powering the compressor running through the crawl space?
In theory you could monitor your mini split's power, but you'd need access to both legs of the 240V circuit individually. This would be easiest at the main breaker, the compressor, or an intermediate disconnect if one exists. Based on the picture, you'd also need access to a standard 120V receptacle to power the device. From online sources, it looks like an alternate power supply was available as well. That one connected directly to one hot leg of the panel bus and to the neutral.
I've never used one of these models, just sharing what I've learned during my few minutes of research.
