After using currentcost, which is not supported anymore, I was searching for a new system and found IoTaWatt. It looks exactly what I need.
To be sure not to forget anything here my system:
3 x 10 kW Kostal Solar converter, 3-phase.
3-phase AC industrial electric system, 230/400 Volt, 250 Ampere with 40 time reducing converters (I don’t know the correct word).
Synology DS111 NAS with PHP 5.6, mysql, at my home.
VPN from home to the factory, where the PV system is (two FritzBox 7390).
What I think that I need:
1 x IoTaWatt with Power Supply 5V DC, AC Voltage Sensor Adaptor.
6 x 100A max clip-on current sensor CT
I would like to see produced solar energy, used AC energy and the difference (plus or minus). I need to know this so I can see if it is better to sell the power or to use it by myself.
Does this system work with Emoncms on the NAS?
Thanks a lot.
This is over my head, so I don’t want to say if it would do what you need. The iotawatt can measure the power of multiple phases, with three reference transformers, but I think you would need to have an electrician look at your setup and determine where and how to measure the things you need.
Sorry I can’t be of more help.
curious when you sell you have different tarrifs depending on time of day???.. do you sell cheaper then what you purchase at… most places I know they either buy at a premium or at the same rate they sell at… I have yet to seen a company that bought lower then what they sell at for home distribution. or in the US some states do not buy your excess power . you only get to to use their grid as a “battery” if you produce more then you need over the year then you get no benefit… if you produce less then you only pay for what you consumed
I have a similar setup running: a (homemade) IotaWatt with 3VT’s connected (each phase one). With this you can measure the use of every phase independently.
My solar inverter is only 1 phase, but the main setup should be the same:
- 1 CT per phase of the inverter (be carefull, your ct’s are rated at 100A and you say you have a 250A connection?)
- 1 CT per phase of your main connection
Configure the inputs and and enable “allow negative power value” for the main connection.
The rest is how you want to configure it and get the results. I guess you just want to know the totals, so create an output in Iotawatt combining the results for 3 phases of the mains and one for the 3 phases of the solar.
You can visualise the result in emoncms.
I use a feed in emoncms that’s combining the 3 phases of the mains and not on IotaWatt (everything was already configured from the old power measuring system before IotaWatt.
That said, your connection seems quite heavy (i havent seen that big 
and not sure what '40 time reducing converters ’ is) so i shouldn’t be telling you to be very carefull and consult an certified electrician if needed
Thanks. I continued on an other treat: IotaWatt three phase discussion - #29 by overeasy
May be you can follow there.
That’s this power converter, going to the meter which measures my power consumption. it has a lot of copper 
. You can still see the old CT from the ‘currentcost’ installation.
Yikes! Is that stuff hot?
I think it too is just a CT clamped around the busbar. It reduces the 200A through the busbar down to 5A to bring it into the range of your revenue meter. What does the wiring look like at the meter end? I’m amazed they give you that much access to what is effectively the internals of their metering. Did you need to break any seals to get to that? It looks very easy to tamper with… although also very easy to kill yourself in the process.
Looking at that setup, you are going to have a hard time figuring out how to calibrate a CT that is clamped to that secondary where the old “currentcost” ct is connected.
My recommendation, would be to use three SCT019-000 CTs on the primary cables that connect to the bussbars. They are rated at 200A and as connected to the IoTaWatt could handle up to 250A if they don’t saturate (haven’t tested for that). I notice that the “power converters” are only rated 200A as well.
The opening in the SCT019 is 19mm, so measure the cable first. It looks close.