240V AC Reference without a Neutral

I am considering the IoTaWatt. I currently have an existing power monitor that uses Z-wave and has no AC reference input. My Mini-Split HVAC shows high power levels when the system is “off”, I believe that this is due to incorrect calculation of power with a default voltage assumption. The appeal of the IoTaWatt for me is that the voltage is monitored and power factor, apparent power and real power are calculated. I am hoping that this would result in a more accurate depiction of my power consumption from my HVAC.

My problem is that there is no neutral wire to my HVAC subpanel with the breakers that feed the systems. Consequently, I have no access to 120V at this subpanel. I have been looking at potential solutions for this prior to ordering an IoTaWatt.

One thought was to get either an EU or UK IoTaWatt system. The problem is that the AC Reference transformers are all “wall-wart” types. This would require an appropriate receptacle for the chosen 240VAC reference transformer. I found this posting, refererence transformer / 3268. The response was that there was no wire-in transformer with known phase characteristics that could be used.

I found a fiberglass (for the WiFi) NEMA box that I could mount the IoTaWatt module and receptacle for a reference transformer, if I can find a good solution. The CTs could be in my panel, and I would feed the CT signal cables through a conduit to the NEMA enclosure. (Weatherproof of course)

Any others have this situation where a neutral is not available, consequently no 120V? Any suggestions?

Thanks, Greg

The 240V VT would work fine. In my house I have a 240V US style plug (one blade is at a right angle to the other). I then use a universal power strip with the plug changed to a mating male version of the 240V plug. It’s a kludge but all off the shelf.

BTW, I no longer can get 230V or 240V transformers. The website has information about where they are available in Europe.