Hello from (actually) sunny Hampton

[Stuart444]

Further to that, I noticed that with the kettle on, the inverter was still only showing an export (I think) of 600W. The kettle was getting its power from the grid. However I thought it was supposed to supply first from PV, then batteries, and finally grid. The batteries are 100% charged, and I'm getting 300v from the panels. So it's still not working as I expect.

[Fintray]

How does the inverter measure import/export as you don't show any CT clamps that connect back to the inverter?

[Stuart444]

How does the inverter measure import/export as you don't show any CT clamps that connect back to the inverter?

On its own, the inverter doesn't seem to have the facility to measure import/export current. If you look at my pictures of the panel, it's in 4 groups.
Top shows the batteries being charged or discharged.
Right shows the PV incoming. It alternates between the two "strings" but these are actually just the single feed wire split into 2 for the 2 inverters that are inside the case. Currently showing about 300v and 0.3A, 100W.
Middle shows "AC output" and alternates between volts and frequency, and power (W and VA). The first two are usually as expected, but the latter two don't show anything but zero, even though my clamp meter is now showing about 600W. This has always puzzled me.
Left is "UPS". This shows much the same as the middle, although I think it relates to the second (in my case unused) inverter output.

There are 2 sets of connectors for AC on the inverter. One says "AC input" and the other says "AC output". Sounds straightforward, but it isn't. The "AC output" is for the UPS, and Voltacon's videos go to pains to point out that it is to be connected to loads only. I hve it connected to nothing. The "AC input" is actually for connection to the house AC, and brings power in (eg to charge the batteries) and power out (exported PV and battery energy). That goes to my garage consumer unit, via the flat twin & earth wire that presently has my Owl meter on the live conductor. That's the way I have set it up, anyway.

So I would have expected the centre part of the panel to show the same current as the Owl meter shows. At the moment, my batteries are full and "charging" at zero amps, the sun is shining but the PV power is low, ~100W in one string and zero in the other. The Owl is showing ~600W, and the AC output as always shows ~240v, ~50Hz, 0 VA, O W. So that doesn't add up, whichever way I assume the "output" is going. The Eastron is showing 250W incoming. Our house usually uses at least 400W (freezers, fridges, fish tank etc), so overall it doesn't look quite right either.

[Fintray]

Ah, I see that the Eastron smart meter connects back to the inverter for import/export readings. Can you confirm that this communication is working correctly?
You say the middle part shows AC output but wouldn't this just show a load if something is connected to the AC output connector?

[nowty]

I've had a read of the manual which is not great. I'm not convinced the battery will output back feeding onto the "AC In" connection at all, it might only output onto the "AC Out" connection. I'm not 100% sure though.

The only info I can see about the Eastron energy meter is at the end of the manual, where it says you can use this to allow the PV to run the normal house loads which would be between the grid and the "AC In". And for that, according to the manual you need to be in operation mode as “Grid-tied with backup II”, I note your currently set up as "Grid-tied with backup IV"

[Fintray]

Have you actually set up the peak and off-peak times whilst in Grid-tied with backup IV as this could also be stopping the battery from supplying the loads when the PV is insufficient? Also note in this operating mode it states "Feed-in to the grid is disabled in default".

[Stuart444]

Ah, I see that the Eastron smart meter connects back to the inverter for import/export readings. Can you confirm that this communication is working correctly?
You say the middle part shows AC output but wouldn't this just show a load if something is connected to the AC output connector?

The manual says that only 2 wires are needed and specifies which pins at both ends. It says that if the phone symbol doesn't show in the Eastron window, then reverse the wires (it's easy at the Eastron end) and see if that makes the symbol come one. That's exactly what happened for me, so I believe it is communicating, but can only assume it is the correct information.

Yes, if the middle part is for displaying output to "AC out" then it would read zero. From the way the panel appears, I'd thought it was for display of export via "AC in", but maybe I'm wrong. Certainly as I have nothing connected to "AC out", then it should read zero in that case. The odd thing then is that it does not display AC output via "AC in" at all, and I'd have thought since that is for grid tied mode, it would be a key parameter to display. The instructions, and Voltacon's videos, are not clear about this (and other things).

[Stuart444]

I've had a read of the manual which is not great. I'm not convinced the battery will output back feeding onto the "AC In" connection at all, it might only output onto the "AC Out" connection. I'm not 100% sure though.

The only info I can see about the Eastron energy meter is at the end of the manual, where it says you can use this to allow the PV to run the normal house loads which would be between the grid and the "AC In". And for that, according to the manual you need to be in operation mode as “Grid-tied with backup II”, I note your currently set up as "Grid-tied with backup IV"

I agree, the manual is not great. I have tried "Grid tied with backup II", I didn't notice any change in export ability.

My wiring of the Eastron is as they show in that diagram. It shows a stand-alone output from "AC out", which I believe is supposed to be UPS loads, and the inverter is also connected to the AC of the house, presumably via "AC in". As a chemical engineer used to piping systems with pressures and pressure drops (analogous to electical systems!) it make sense to me if the inverter maintains an output voltage a bit higher than the grid voltage, then house loads will pull from the inverter and input from the grid will be zero, until the house load exceeds the inverter's output limit, when its voltage will drop slightly allowing grid AC to fill the shortfall.

Maybe I should contact Voltronic for comments. At the end of the day, if nothing works, I'll be forced to go back to Voltacon with a suspect failed inverter. But as I said, because we disagreed on the issue of the inverter being in the ENA register, I'm not expecting them to bend over backwards for me. I've just noticed that I bought it all on 31/3/23, so it looks like it will go out of warranty unless I can nail it this week. I did get output from it without it being connected to AC in some months ago when first commissioning it, so it's probably not broken, but I was just learning how it all worked then. I think tomorrow I'll wire a load to "AC out" and see if it exports to there from PV and batteries. I'll also disconnect the incoming AC and see if it exports to that as well.

[Marcus]

I aren't even going to try and figure out the setting - I'll leave that to the others

The only thing that occurred to me was that your meter is reading negative on import and that you have the grid supply going in the bottom meter terminals and the feed to the henley blocks (and the house) coming out the top, which is opposite to the diagram (grid in top, house into bottom) - could it be as simple as the inverter sees a negative power as 'export' and it should be positive for export?

i.e. It may be trying to reduce the -600w to zero by reducing it's output (from zero) - but cannot reduce it's output below zero (due to a full battery).

[Stuart444]

I aren't even going to try and figure out the setting - I'll leave that to the others

The only thing that occurred to me was that your meter is reading negative on import and that you have the grid supply going in the bottom meter terminals and the feed to the henley blocks (and the house) coming out the top, which is opposite to the diagram (grid in top, house into bottom) - could it be as simple as the inverter sees a negative power as 'export' and it should be positive for export?

i.e. It may be trying to reduce the -600w to zero by reducing it's output (from zero) - but cannot reduce it's output below zero (due to a full battery).

Thanks Marcus - lateral thinking is what I need! I think you've hit the nail on the head.

I have my grid connected to the bottom of the meter, and the house (and inverter) connected to the top, where the signal wires go. Eastron's user instructions don't show how to wire it up. However I found a youtube video which clearly states that the the inverter is connected to the bottom of the meter (bottom when the writing is the right way up), whereas it was convenient for me to wire the bttom to the AC in. I figured it is bidirectional so it didn't matter. But as you say, maybe that gives an inverted signal output and so the inverter is refusing to export as it thinks it's already exporting to the grid which its setup says isn't allowed.

So, another job for me today. I know that reversing the signal wires stops the communication, but maybe there's a setup parameter in the meter which inverts the reading. Alas the user instructions go on about baud rate, parity, pulse length etc - all a bit double Dutch to me. I can't see anything obvious to change that would make it work with the meter connected backwards! If it were possible, that would be much easier than physically turning the meter upside down, but if I have to, I'll do that. I've sent a query to Eastron Europe to see if I can invert the signal, but being Sunday today, I don't expect a reply until tomorrow at the earliest. Meanwhile, I can try the other tests I planned.

Thanks for all your help, you are stars