Help please - new install Australia

Hello all.

I’m interested in having IoTa installed at our house. We presently have Solar Analytics but because we are on 3 phase it doesn’t allow a level of granularity where I can chase down excessive consumption.

Our setup is as follows:

3 Phase
One sub panel
15KW solar inverter

I believe that I would need:

1 Standard Base V5
3 AccuCT 100A x 16mm split-core (1 for each phase)
1 additional AccuCT 100A x 16mm split-core for the solar inverter
11 AccuCT 50A x 10mm split-core
1 VT
Power Supply

Am I missing anything? One other question I have is would the power draw at the sub panel simply show as a single circuit or is there a way to gain more detail than that?

Thanks in advance. Steve

IoTaWatt has14 inputs and you specify 15, so looks like one extra.

Your solar appears to use a three-phase inverter, so that would require 3 x 50A. The sub-panel feed would require 3 x 50A. After the mains, that leaves 5 additional inputs. You have a three-phase water heater. All the rest appear to be single phase.

The sub-panel appears to have the bulk of the circuits. The main panel feed will give you the power used by each phase, but not any further breakdown. You would need a second IoTaWatt there to break that down.

Thanks for the detailed feedback.

You are correct about the inverter. I hadn’t considered that.

I’ve no issue installing a 2nd iotawatt. I guess my only concern is the integration of the data, but I’m guessing that’s not an issue given enough time and patience?

I’m not too concerned about the 3 phase water heater. It’s for a guest bedroom that gets used only very occasionally.


For the main panel:

1 IoTaWatt
1 power supply
1 VT
3 AccuCT 100A x 16mm split-core (1 for each phase)
3 x 50A CT for the inverter
3 x 50A CT for the sub-panel
5 x 50A CT for monitoring A/C, Hot water, Pool, Septic etc

For the sub-panel
1 IoTaWatt
1 power supply
1 VT
14 50A CT

Thanks again,


Looks about right. For Australia, I recommend acquiring the VT and USB power supply locally as you have a unique plug type and the VT is heavy therefore expensive to ship. There are links to local suppliers in the Aussie Bundle web store page.

Aggregating the data from multiple IoTaWatt requires using an external database like influxDB or Emoncms,. Uploading to either is fully supported but building a dashboard or othe reporting medium would be beyond the scope of the IoTaWatt project. That said, many users have been able to do it.

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Hi Steve,

where are you located? I’m just west of Sydney.

I have a single IotaWatt installed (about 3 years now) and my mate Pete (bluetardis on Iotawatt) has 2 IotaWatt monitoring a 3 phase system with 28Kw of Solar on 2 inverters (1x3 phase, 1xSingle). 3 phase water heating is unusual. We are both on an external emoncms server that I maintain on AWS.

You should be able to see my system at

and Petes at

We have only just migrated from Azure so there are a couple of virtual feeds that need adjusting but you should get an idea of what a single and/or multi IotaWatt system can produce.

Happy to help if required.


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BTW - Pete has a 3-Phase Sauna on a sub main so would be aware of how this can be done.

Hi Tony,

Thanks for your message. I’m up on the Tweed.

The water heater is a 3-phase instantaneous. Good for what we’re using it for and it’s really small. I think they’re more of a thing in Europe.

I’m really keen to get this thing set up. As I mentioned in my original post I have Solar Analytics but it doesn’t really do what I want. As an example I’ve got something using a lot of power at the moment and I’m having to isolate it by turning off circuit breakers. Have narrowed it down to the septic pump but would be a lot easier with more detail like the IotaWatt can provide.

Thanks for the offer of help, I’m fairly sure I’ll need it!


Not to hijack, but been looking at the same situation of having a SolarAnalytics (3 phase) and wanting to get more granular level of data, but wondering would the existing SolarAnalytics and its’ CT clamps interfere with adding an IoTaWatt ?

Or can both systems and their clamps run in coexistence? If they can coexist, are there any caveats, i.e. CT clamps on the same cables must be separated by x cm/inch etc?

As long as they can loosely fit physically, should be OK.