Industrial multi iotawatt / multibuilding feed monitoring..need help designing

Good morning/afternoon (depending where you are on our giant rock)

I’ve been running several iotawatt’s at my homestead, and because of my experience, and the capability of these devices, have recommended them for a a number of projects to others - and one is where I work. The initial value was for our environmental impact reporting metrics, with our on-site solar and electrical mix… however a need has arose to look at a main switch gear feeding several buildings for a load study for a new building being designed. So, myself, and the project manager has decided the value in this project is now twofold and have been given the green light to proceed with this project, and are planning for our outage to do it.

The inspiration is the case study of the IoTaWatts that was put up a couple year ago in a 277/480 industrial site. Our main switch gear is 480 3ph, with several 600a and 800a feeds to buildings. In total the switch is feeding 13 distribution panels, with a capacity of 19 feeds. So I know currently I will need 4 iotawatts for this location alone.

My question is regarding installation (hardware limits of the iotawatt).
Can I use one VT for a reference for each iotawatt (I understand ideally I need one VT for each phase; but can four iotawatts use the same three VTs for the power reference?)
Or would it be better to install 13 IoTaWatts in each of the buildings in the MCC rooms (which I cannot guarantee there is great, if any WiFi coverage being a Class 1 Div 1 rated area portion of the plant.)

Also, has there been any POE/ethernet connectivity options developed/available? WIFI is great, but sometimes good 'ol copper is already in place.
Also, I need some availability and sources for 600a, 800a, and 1000a CTs; and some VT recommendations.

If I can make this work, I think we’ll have our justification to roll this platform out site-wide… which is a large project, I’m very excited to be able to do it!

That site just passed 1 GWh. It has 20 months of data.

Maybe more than 4.

In that installation above, we used three transformers, but the first week I monitored using both “Derived” reference (one VT) and “Direct” reference (three-VTs) There was no appreciable difference. There is also no significant difference in voltage between the phases. I expect the same for your installation.

Yes, the IoTaWatts that are co-located can share one or three voltage references using commodity splitters available from CCTV supply sites. It is imperative that polarity be maintained, so I strongly recommend using standard splitters.

When you share VTs, it is important to use separate USB power supplies for each unit. Sharing DC power causes ground loops that throw everything off or worse.

The only communication is WiFi. This is an electrical limitation of the hardware and there is no way around it. You can run copper to the area and then use an inexpensive AP to go the last couple of meters.

Usually higher amperage service is supplied by multiple parallel cables. That site mentioned above has two cables per phase with 400A CTs on each. I stock 400A and 600A. I can get larger, but they are very expensive. I would need to know the detailed requirements to quote price/availability. I have previously supplied 800A x 55mm.

For the VT, I used ELCO ETR12-277. They’re about $35, and mount directly to a hole in a box. Output is 12V (OK for IoTaWatt) and you need to add output barrel jack for 12V side. They are in the IoTaWAtt configuration tables as AX-27750-H.