[QUOTE=Snoogans;2527164] I think the part that may be confusing you is that CT meters are also provided a Voltage reference from the same conductor which allows power factor to be calculated.
Thanks, that was what I said in the last post in a roundabout way. I don't think I'm confused, I think I'm either ignorant or stupid. On the other hand it is possible that I might just be too confused to know if I'm confused or not!
So am I correct in thinking that at a physical level in terms of flux generation, the CT will produce an output which is proportional to all the current flowing through it, both real and reactive, and it's only by taking into account the phase of the voltage that the real (i.e. non reactive) power is calculated? I'm sorry to say it's a long time since I did my studies and they didn't include current transformer theory!