Hello, its been a while!
I have a heat pump with a 6kW 3ph star electric accessory heater
I thought it wasn't working properly, and to cut a long story short, I clamped the terminals, and got a load reading on only one phase.
I have drawn it out, to try and make sense of it. I have a theory as to why its working as it is, but ill get to that in a later post.