I was on single phase until last month. It was indeed very simple back then. I had a current cost with two clamps to monitor two things
After upgrading my house to three phase power (to charge my car quicker) I got the iotatwatt.
I have 6 clamps, 3 connected to each phase, all circuits wires go through those clamps according to the phase they are connecting to.
The sub-circuit for my pool/spa is on another clamp (though connected to phase1), and then the 2 solar each have their clamp (solar 1 is on phase2, and solar 2 is on phase1)
I have one reference voltage linked to phase3. Phase1 and Phase2 are derived from that (the powerboard is by my door entrance in the all way. If I was to add two more GPO there my wife would kill me, it already look messy enough)
In the output iota setup I’ve set Total to be : phase1+phase2+phase3+pool
Then I have Total_Solar that is solar1+solar2 (both are negative).
so my net feed should be: Net_Feed Total + Total_Solar
I set Import as
Phase1 + Phase2 + Phase3 + Pool + Solar1 + Solar2 max 0
And Export as:
Phase1 + Phase2 + Phase3 + Pool + Solar1 + Solar2 min 0
When I look at the data output, it seems right, and match +/- 10% what the inverters are saying.
For the actual power usage, all I can say is that I’m 100% sure every single circuit is covered and going through a clamp.
|Phase3_VT|VT, Powertech MP-3027(Aus), phase:A|
|Phase1|CT, ECS16100, phase:B|
|Phase2|CT, ECS16100, phase:C|
|Phase3|CT, ECS16100, phase:A|
|Pool|CT, ECOL09, phase:B|
|Solar1|CT, ECOL09, phase:C|
|Solar2|CT, ECOL09↺, phase:B|
Getting the phase in the input settings was based on trial and error, by plugging something of a known load and playing with the value until it reads what I was expecting.
I can guarantee you I’ve read the iotawatt docs about a dozen time (superb docs btw, talking from experience that alone must have taken more time to write than the entire project code)
I do have a rather large voltage difference between the three phases, particularly when the solar is producing at its max. I’ve seen up to 5V difference. So +/- 2% which I can live with.
The 2nd graph is the one from the iotawatt directly.
I roughly now how much devices in my house are pulling when running, and so far the Iotawatt’s Data screen have always matched fairly accurately what I was expecting to read. Certainly much better than what the CurrentCost device did (but that’s because it didn’t have a reference voltage and was using fixed 230V)