Expanding system

Getting Started
1

Now i have the emonpi2 working (thank you again @Robert.Wall) i am looking at expanding my system.

We have 2 CU’s in the garage, one will have a emontx5 12 ct clips on it, the other will have the emonpi2 with 6 ct clips. The pi2 will control both etc.

This is a photo of where the emonpi2 is going

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The two gray wires at the bottom left (bottom circles) go to the backup box to the right.

This then goes to a Henley box, along with a import / export from the solar inverters. It is also connected to the house load, via an isolation switch (box on left)

What i would like to monitor are

Mains import/export
House import
Solar import/export on both inverters.
Adding EV at some time, do not know where feed will be.

Now the way it works is, if one inverter battery is full and the inverter is still producing energy it is transferred to the other inverter to help fill its battery. If both batteries are full etc then it will export to grid.
All done via the Henley block / fuse box.

So am i correct with the following

100amp ct clip on mains
100amp ct clip on feed to house
50amp ct clip on solar inverter 1
50amp ct clip on solar inverter 2

The two spare ct’s for expansion.

2

I can’t see where your main incomer is, so I can’t figure out what feeds what from where. If you’re confident you can get 4 c.t’s on 4 cables where each only sees the power going to one of those 4 items, then that’s good. If you can’t, you’ll need to add and subtract on the inputs page of emonCMS to extract the values you need. If you do this, beware of the error you might lay yourself open to if you end up subtracting two nearly equal values. Also beware that while all 6 channels in the emonPi are reported at the same instant, and the same is true of the emonTx, the emonPi and the emonTx are not synchronised to each other, so there will be a time difference, and an inconsistent one, between the two sets of readings.

3

The mains comes in from bottom left to the backup box, which controls all import / export.

I was hoping you would say somthing like that means ill just have 4 ct clips and yes theres more room around the wires in places.

Found a talk on working out import / export on the one feeds.

Not worried about the two being in sync. In total i have 6 to put in over time and as long as i get them talking with Home Assistant ill be happy

Cheers

4

I couldn’t see the wood ( = forest) for the trees with your picture. It was too close.

I’m sure plenty of examples of that are on the forum, the problem is finding them. The idea is to use the “allow positive” and “allow negative” in the input processing to direct the power/energy into two separate feeds – so “allow positive” and send to the import feed, then reset to the original value and do the opposite (negative & export).