Solis hybrid inverter with no CT clamps

[Displaced]

Hi everyone.

I have a Solis S5-EH1P3.6K-L Hybrid Inverter. It was installed July 2023 and has been running with no problems. Any generation feeds the house during the day and excess get pushed to the grid which I get paid for, Which I can see via the octopus app.

I’ve got the Solis app setup and that works well and I can see the level of solar generation.

I recently got a zappi car charger installed and noticed I can now see in the zappi app more information about my system than I can via the Solis app. I can see levels of what the house is using, what’s being generated and how much is coming or going to the grid.

Now this made me think I should also be seeing this in the solis app (it has the same kind of logos for house, grid, solar, battery etc) but it has never worked like that for me. When I researched the install manual I can see that there are options for CT Clamps which I think have never been installed.

My question is can I install these fairly easily myself? The other issue is the inverter is in the loft and my meters, feed in are all on the ground floor.

Many thanks for any support and guidance.

 

[chrisski]

I’m not familiar with your system, but for my case I would need to install CT clamps around circuits to find my loads.

Emporia does this

Emporia Energy: Revolutionizing Home Energy Management

Home energy management made easy. Save on energy costs with the Emporia Home Energy Management Platform.

www.emporiaenergy.com

It also sells plugs for 120 volt chargers and EV chargers.

I have found 1/3 rd my winter energy comes from 240 volt EV charger and 4/5 from 240 volts in the summer with Three air cons and an EV charger.

Something like emporia will let you do a good load study. That could take six months to a year to get good data.

 

[rpdom]

I'm surprised you haven't got the CT clamps and meter fitted. I'm sure they come as standard with that inverter (I have the S5-EH1P3K). They are essential for proper hybrid operation with batteries.

It may be possible to buy the correct meter, but I believe Solis makes some custom settings on the meter to work with their inverter.

Maybe @SeaGal or @peufeu can help?

 

[peufeu]

When I researched the install manual I can see that there are options for CT Clamps which I think have never been installed.

That's weird. At night it pulls just enough power from the battery to offset what the house is using without exporting to the grid, but it order to do that, it needs to know how much power the house is using, or at least measure grid export, so it needs a meter or a clamp.

Unless the whole house is wired to the backup port, or you're not using any battery perhaps?

What is the inverter doing with the battery at night? Is it discharging?

My question is can I install these fairly easily myself?

Yes

The other issue is the inverter is in the loft and my meters, feed in are all on the ground floor.

You'll need to run a twisted pair cable for Modbus to the meter.

My Solis S5 EH1P6K came with an Eastron SDM120 in the box, but since the house is wired for three phase, I got an Eastron SDM630 from Aliexpress. It works fine. I used the Solis provided SDM120 to measure the power on my EVSE instead, it behaves as per the datasheet so it looks like the normal model. The two inverters also work fine with my smartmeter emulator, so I know the inverters don't make custom modbus requests. So I guess these inverters would work fine with the meters mentioned in the manual (Acrel and Eastron).

 

[Displaced]

Unless the whole house is wired to the backup port, or you're not using any battery perhaps?

No, I don't have a battery yet, but this has what has started me down this path of discovery. As well as getting the car charger.

You'll need to run a twisted pair cable for Modbus to the meter.

twisted pair? would some unused CAT6 ethernet cable work? I have some already unused, embedded in the walls that I could repurpose.
Are there any wireless devices that could be used to 'transmit' the signal from the clamps to the inverter?

Eastron SDM120

Is this the CT Clamp or something else?


Thank you @peufeu for your detailed response and thank you to @rpdom for the mentions.

 

[Displaced]

These are the items that have been left by the installers. I know which one is the CT clamp but not sure what the other items are.

 

[rpdom]

The third picture is the cable to connect the meter to the inverter. The fourth picture is the meter and CT clamp.

You can extend the cable from the inverter by using twisted pair cable, like ethernet cable (use just one pair). The Solis inverter manual says how to connect the two wires to the meter.

[edit]
The meter is usually fitted alongside your inverter main breaker in the consumer unit, on a 6A breaker of its own. The clamp is fitted around your main incoming live wire and the wires connect to the little meter.

 

[Displaced]

This is all starting to make sense now, thank you @rpdom.

I've just watched this video also which seems to talk around this part of the installation.
Solis Installation Guide Section 3 CT & Meter Monitoring Options

The cable in picture 3 which connects to the inverter one side and then to the meter is not long enough in my scenario, but the video seems to indicate you can extend the cable. Which I can hopefully use at least one set of twisted pairs in the unused CAT6 cable I mentioned in a previous post.

I'm trying not to be slightly annoyed that this wasn't done by the installers, I remember asking about the info in the app when it was demo'd and they said that the grid and house usage was not a feature of this inverter. Which I think was blatant lie because they couldn't be bothered to do it.

but anyway, I like to learn new things so this will be fun. May help me when I buy a battery and I could potentially install it myself

 

[rpdom]

I'm trying not to be slightly annoyed that this wasn't done by the installers, I remember asking about the info in the app when it was demo'd and they said that the grid and house usage was not a feature of this inverter. Which I think was blatant lie because they couldn't be bothered to do it.

It absolutely is a feature of that inverter. Like I said, I've got the next one down in that range (with batteries) and it shows those details. True the inverter can run just fine without the clamp and meter if batteries are not fitted, but I don't see the point of not fitting the supplied equipment like that (as you say, probably just being lazy).

 

[peufeu]

OK that explains everything

they couldn't be bothered to do it.

Hey at least they left the gear that you paid for instead of pocketing it

Without battery, you only need a meter to limit export. Since you don't limit because you're selling the electricity, it works fine without meter.

However if you install a battery, or if you want the extra information provided by the meter, then you need the meter.

The one you got is the standard SDM120CT meter which I also got with my inverter. There are detailed installation and configuration instructions in the inverter manual for this meter.

The CT clamp is directional, it measures import/export according to amplitude and direction of current in the wire. If you install it wrong, you'll get the wrong sign on power. If you swap Phase and Neutral on the meter, it also flips the sign of measured power. There's also a setting in the inverter to flip the sign in software. If the sign is wrong, house power displayed by the inverter will be wrong.

To extend the provided cable, you can use pretty much any twisted pair cable. Cat6 will work but the wires are quite thin and fiddly and tend to not make reliable connection in the meter screw terminals, especially the stranded versions. They also break easily. Crimp ferrules help a lot to make the tiny cable core fit in the screw terminal. Cables with thicker solid core wires work better in those terminals, like standard telephone cable or Grade 3.

 

[SeaGal]

Hi... I'm a bit late to this party. Looks like @rpdom and @peufeu have covered all the key bits in their replies . Hope you get it / have got it sorted.

 

[Displaced]

Bit of an update and a shout out for more help

I've managed to get the CT Clamp and the Eastron SDM meter installed. I've had carpet up to get to floor boards, routing cables through small gaps.... it's been fun.

The meter was displaying information and I checked it was set to the correct 100A to match the CT clamp.

I was expecting the inverter to start displaying this extra info, but it's not just yet. Do I need to update some settings on the inverter to let it know there is now a meter installed?

 

[rpdom]

Yes, you'll have to change the meter setting on the inverter form "No Meter" to "Eastron 1ph meter".

That should be in Advanced Settings -> Storage Energy Set -> Meter Set on the inverter screen.

 

[Displaced]

Big thanks to everyone for your support. Looks like its working and the numbers are similar to what my Zappi/Havi are showing so looks like a success.

Really pleased that I got it working.

Now I'm off to research some batteries and how to install them

 

[Displaced]

This may be a stupid question and I can’t believe I’ve not noticed it before. But because I’ve attached the meter now I was expecting round the clock data. But the inverter goes offline when there is no solar being generated. I guess it makes sense but not something I realised, I just assumed the inverter was powered by the mains not the panels.

Is this correct or am I missing something?

 

[kommando]

Varies from inverter to inverter, my SMA's turn off, my Solax's stay on. I have an external monitor so no issues for my setup.

 

[rpdom]

Solis inverters are powered by the panels or battery. With no battery they turn off when there is insufficient PV generation. It would be wasting power to have them stay on.