Does solar input need one or two CT's?

The ordering page says you only need one 50a CT to monitor up to 12kw, but I’ve read in posts that you can’t just double the output if the device has a neutral wire. My Solar output (6kw) back feeds into a double pole breaker and there is a red, black, and white wire coming into the panel from the inverter. I would assume most solar installs are like this, no?

I can’t say what most are, all I can say with confidence is that many are two-wire.

If you have three-wire, you can use two 50A CTs, or for a 6 kW system you can use one 50A CT on the red and black wires with one passing in the opposite direction from the other. It’s really no different than a 240V three wire load like a clothes dryer.

Thank you for the response. I went ahead and ordered two of the CT’s because there isn’t enough spare wire to run one of the wires through the opposite way. Just for my own edification, what would happen if you just used one CT? Would one leg potentially use more/less power than the other because of the neutral?
The wires are back feeding the panel but is it possible the inverter needs 120v from the panel?