3 Phase Question

I’m running an emonTx with 3 phase firmware to monitor an air source heat pump.
emonTx has an AC adapter connected.
Can I CT monitor just one phase of the input to the ASHP and multiply by 3 to get a reasonable idea of the total power consumed by the ASHP?
Does the CT need to be on the same phase as the AC adapter?

If your ASHP represents a balanced load, then yes, and you don’t need the 3-phase sketch in that case (but any other c.t’s that you use must be on the same phase, or you can have apparent power only).

That is answered in the comments at the top of the sketch.