DIY ESS - Pairing a Second Transmitter on a Wattson

I thought about this maybe a year ago and was not sure it could be done until I read more about Wattson and its capabilities: It can get signals from up to 10 (!) Transmitters

The idea here is to send Generation Power from different locations:
- First, the generation info from the Solar Installation
- Second, the DIY ESS - Energy Storage System - output generation
These two add up automatically as long as they are paired to the same Wattson display unit... => Cool !

On the pictures, you recognize the white Wattson that is already paired to my Solar Installation + ESS (off at this moment)
To be able to compare values, I brought the Silver Wattson upstairs;  It is showing Solar generation only
After pairing the second Transmitter you can see on the floor here, and plugging in a clamp/CT into the generation inlet of the Transmitter, this new "Generation" adds up to the Solar Generation, meaning we can now have a clamp + additional Transmitter directly in the DIY ESS to measure the ESS only Generation and no additional outlet to install in the Solar sub-panel / junction box - like I did with my Solar contractor -



Using Generation inlet only

For testing purpose here I am measuring a small load from few lamps - LED of course -, from my home made Easyfit Y Cable from few weeks ago

On the left, the white Wattson adds up the 2 Generation signals it receives from the 2 Transmitters,  and on the right, the Silver Wattson displays the Solar Generation only

Testing Wattson Transmitter to make it work for the US & Canada SplitPhase Consumer Units - Part 2

Last night, I did continue my testing to try make Wattson work for Split Phase AC installations in USA and Canada

First I started to draw and write down what I know

On the left I drew a consumer unit with 2 distinct phases lines and their set of breakers, leading to 2 different loads: Here one CT clamp / Current sensor on each line and plugged into Wattson input 1 and 2, will result in displaying the total Usage, with Wattson settings adjusted to Voltage = 120V and the latest version of Holmes, Holmes2 allow that now.

On the right is the Generation side with the Grid Tie Inverter, from Solar or Wind, feeding power into the 2 phases in 240V.

Here with one CT clamp / Current sensor we will have a reading of half the power generated only: we need to double it ...

I read earlier this week that, in order to do so, we just need to wire 2 CT clamp in series, and their voltage should add up !

Almost solved then... But how do we do this ? Well this is exactly what the Easyfit Y Cable does, and to double check that, I drew it on the lower left corner from pictures I took of it earlier and also removed the one I using on my Solar Inverter & ESS line;

I then plugged 2 CTs into it, plugged the end of the Y cable into Wattson 1 input and it displayed the Usage x 2 :-)

After that, I did plug one CT into Wattson input 1 and the 2 CTs with Y cable into Wattson Generation input, and the Net Usage displayed is of course Usage - Generation, and negative here 

So it looks like it is that simple in the end :-)

I completed my drawings and notes with that