Hello from (actually) sunny Hampton

[Countrypaul]

Hi and welcome,

A diagram of how you have things connected up (or how you believe you have them connected up ) would be a good starting point along with photos of the various parts/connections and an explanation of what is not working as you expect.

[nowty]

Welcome Stuart444,

My ex work colleague lives in Whitchurch, nice canal walk, cracking pubs and curry house.

I'm sure we can help, so you have one of these,

https://www.ledandsolar.co.uk/shop/hybr ... ry/655.htm

User Manual
https://www.ledandsolar.co.uk/downloads ... 20Inverter

As Countrypaul says, tell us more.

[Fintray]

Am I missing something about Stuart444?

[AE-NMidlands]

Am I missing something about Stuart444?

Yes, the initial post has gone awol, but I read it earlier!
Welcome from me too Stuart, like Moxi (also at about the same latitude as you) I have had a belting day, and as a real novice it is quite exciting. I'm very sorry your system won't play ball.
Without doubt our experienced DIY-ers will have some good advice.
Best wishes
A

[Fintray]

In that case welcome to the forum Stuart444 and could you please repost your introduction?

[Stuart444]

I'm not sure about "awol", but the post on my computer says "This post is not visible to other users until it has been approved by a moderator." But clearly, you can see it. Anyway, I'm glad you all saw it.

Nowty, yes, that's the inverter that I have. I also have v1.1 of that instruction manual, it's hard copy so I guess it came with the inverter.

I've posted some photos below. My panels are in a small field adjacent to my house, 2 strings of 8 panels. These are both in series, then they are combined, with lightning protection, and travel underground in 2" PVC pipe as one pair of wires to another combiner/splitter box in the garage. Here there's more surge protection and it splits into 2 strings again as the inverter is actually 2 units in parallel.

I put this kit in the garage as getting it to where my main consumer units are would have been a nightmare. When we rewired the house 6-7 years ago, we put in a heavy cable to the garage as I planned buying an electric car. So, there's another consumer unit there which feeds the garage etc and the car charger. The inverter's output goes to that consumer unit via a breaker. On advice, I've changed the breaker in the main consumer unit that feeds the garage consumer unit with a "curve B" version (whatever that means. Something to do with how it detects a fault, I think.)

I've fitted an Eastron SDM630MCT-V2 smart meter in series with my Secure Liberty 100 billing smart meter. There's a cat 6 signal cable running from it to the inverter, and the telephone icon is showing which means that it's communicating with the inverter.

I bought all this from Voltacon (Birmingham) in early 2013. It took a long time for me to install, but it has been "complete" for a couple of months now. It charged up the batteries fine, but at present I can't get the system to export more than a few watts to my house.

I've checked several times the various Voltacon videos on youtube, and scrutinised the installation instructions, and as far as I can tell it is all correct. Local PV installers don't really want to help as they worry that they might lose their accreditation for working on a system made by a non-accredited installer, or so they say. One did come over as a favour and cast an informal eye over it, and he spotted a couple of installation shortcomings (incuding the need for a curve B breaker) that I have since fixed, but he wasn't familiar with this inverter.

Whatever load is being drawn by my house, the inverter exports nothing. I put a clamp ammeter on the connection from the inverter to the nearby consumer unit, and it usually shows 16W (0.016kW), dropping to zero if I open the isolation switch.

Voltacon's explanations on youtube are difficult to follow and sometimes ambiguous in my view. They try, but they are not professional educators!

My troubles started when applying for a G99/G98 certificate from my local network operator, Scottish Power. They said this inverter wasn't on the ENA register and they won't grant a certificate without that, unless they do a witness test which costs close to £400 on top of the registration fee. This led to lots of heated discussions and emails with Voltacon, who didn't want to go to the expense of putting it on the register. (It later appeared on the register, maybe done by Voltronic, but only for G99 approval, not G98, which Scottish Power said I need. Hence they still won't approve the system. I'm going to be limited to 3.6kW export rate.) After I threatened legal action, Voltacon agreed to pay Scottish Power to do the witness test. Hence I'm not on the best of terms with them.

I need it to work before calling in Scottish Power's engineer. However, it won't export, so something is wrong. There are a lot of setup parameters, which I've been through several times, and can't see a problem. Clearly it's time for less myopic eyes to help!

I can post any information (eg all the setup parameters) if it helps. I've also posted a diagram below.

[Stuart444]

5 uploads was the limit, so here's the diagram.
It had an error in it, so I've deleted it now. Corrected version is on a later post.

[Countrypaul]

First thing I notice is that there appears to be a CT around a cable just above the Voltacon box. Does that CT go round the whole of a T&E cable and what is the CT connected to?

You also have one battery connected to your inverter and the other batteries connected to the first battery. It seems normal convention to connect either the first or last to one pole of the inverter and the opporite battery to the other pole - someone more familiar with batteries can explain far better than I canat present.

[nowty]

First, two minor points which won't affect the operation.

1) Your wiring diagram shows you have put the Eastron SDM630MCT-V2 within the DNO's equipment zone, they wont like that. It should be on your side of the Company Isolator. Maybe you have not drawn it correctly.

2) (what Countrypaul says), You have wired your batteries in the non recommended way. Because of the resistance in the connecting cables, your battery currents will be uneven, with the highest current flowing in/out of the top battery and the lowest out of the bottom battery.

If the power cables are arranged this way (see pic below) the current should be equal in/out of all your batteries. Which may mean you need a new cable as one is now too short but lets not worry about that at the moment, it will work as is.


Next, do you know what "operation mode" you have set the inverter up as ?, the manual has 7 operating modes, put it in the wrong mode and it won't operate as your expecting.

Next, do you know what "charger source priority" you have set the inverter up as ?, the manual has 3 modes.

Next, do you know what "Load supply source" you have set the inverter up as ?, the manual has 2 modes.

I note it looks as is you have a third party monitoring device, you say "Whatever load is being drawn by my house, the inverter exports nothing. I put a clamp ammeter on the connection from the inverter to the nearby consumer unit, and it usually shows 16W (0.016kW), dropping to zero if I open the isolation switch."

Again as Countrypaul noticed this - It also looks to me as if the clamp goes all around the whole cable (difficult to see clearly) but to work it must go around a conductor, usually the live conductor only. Is it as simple as this ?, maybe the inverter is working but you don't think it is because of a false reading in the third party monitor ?

[Stuart444]

First thing I notice is that there appears to be a CT around a cable just above the Voltacon box. Does that CT go round the whole of a T&E cable and what is the CT connected to?

You also have one battery connected to your inverter and the other batteries connected to the first battery. It seems normal convention to connect either the first or last to one pole of the inverter and the opporite battery to the other pole - someone more familiar with batteries can explain far better than I canat present.

Yes, you are right, I put the CT round the T&E I'd used. It was the only 6mm2 cable I could find in B&Q. I figured it was OK, but come to think of it, in its normal previous life it was round one incoming conductor on the feed from the grid before the splitter box. Daft of me! I've always wondered how these devices work so well given how crude they look. But as it's measuring the field round the wire, I guess putting it round live and neutral is going to mess it up. However, I'm 100% certain it's not exporting, as I expect the batteries to run down when we have a dull day (quite a lot recently despite the thread title!) and there's significant load like the washing machine / tumble drier. I've still got the car charging at night when I get cheap Octopus electricity. Tomorrow I'll split the T&E so that I can put the clamp on the live, and I'll charge the car in the day which pulls 7kW and see if it livens up the export.

Re the battery connection, this system works at 52v (so it's 12 lithium cells in series inside, maybe several in parallel too). Adding more batteries to increase the storage has to be done in parallel to maintain the bigger bank at 52v. You are right, the top battery will run at very slightly lower voltage than the lower ones due to the resistance in the connection wires, but they are hefty wire, even at 100 amps it will be small. I make a lot of model aircraft with battery power using much smaller lithium ion batteries, usually all cells in series but occasionally two strings in parallel. we bung 100A down conductors of maybe 10mm2 sometimes, and the strings are indistinguishable after full discharge. Voltacon definitely instruct them to be wired in parallel, I've seen that with these batteries on some of their youtube videos. So at least that bit is right, I think.

Thanks for your comment!