Quick Solar Setup Question

Just had our solar installed and we are awaiting the ability to turn it up from the grid provider.

I did have one question. Once solar is flowing into the panel, I assume I set my mains to allow negative numbers but the solar input to the panel I would keep as positive only to the panel, correct?

I placed two 50A CTs on #13 and #14 planned for my solar inputs (like my mains with one reversed from the other), but I think I want to keep this as positive only?

Thoughts, direction or pointers? I attached the images from my setup and each of the main and solar inputs.




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Nice, maybe the timing is a little off with the equinox coming up next week. The SRECs won’t mount up for awhile.

I’m assuming your inverter feeds into a circuit-breaker at the bottom of your main panel. The approach is different if the solar is connected upstream of the mains. But assuming it’s into the panel, yes, you set the mains to allow negative values.

It’s pretty much arbitrary whether you make the solar feed positive or negative. It can be made to work either way. The Emoncms folks have adopted a standard of making it positive. That’s consistent with the other feed to your panel - the mains. So the total power being used by your home is the sum of the mains and solar.

In my experience, you can measure the solar with a single CT on one of the legs. Right now you will need to double it when you use or export power, but the release due out next week has a way to configure 240V inputs that should be doubled.

I notice your mains are still configured as ECS24200. They have the same turns ration as the ECS25200-C2, but quite a different phase shift, so you might want to change that.

Yes, but the SMART program is what I am a part of which also includes some extras for those with a battery. That is coming in the near future when supplies are available. :slight_smile:

Yes sir, sorry I was not clear. The new circuit is at the bottom right in my panel and no sub-panels. Negative on mains set and ready for the day I can turn it up and there is sun.

Man, now I have to add a “total_total” feed for my two mains and two solar feeds. Oh well, I will have to work on my naming in Emon for this.

Good to know and thank for the heads up. I did not even think of that after I installed the newer models. I’m off to change that now.

More like these changes I hope:


The convention is to add the mains and solar and call it use. That’s what you are using, so if you have a misc output, you would add the mains and solar and subtract everything that is directly measured from that. Your mains are now import/export.

If you use EmonCMS, you might want to look at the mysolar app and see the feeds that are used and what the default names are.

As usual, full of info and pointers. I will have a look as I think I will need to clean up some of my feeds and rename them as things are a bit more complex adding solar. Thank you sir for the direction.

Looking at the MySolar App in Emon, what are they wanting for the last field on importing? Is that what kWh the solar is importing only? Solar in?

Think I got it. Sorry for the extra effort. It was grid importing. Seems to be working without my solar working. 100% grid. :frowning: