Omnibuswoman Posted December 7 Author Share Posted December 7 You guys!! Honestly, I’ll never get the house finished if I let myself get distracted with this kind of thing, which is right up my street… I will add it to next year’s Christmas present list, IF I’ve finished the house… Meanwhile, there’s clearly a problem of some kind with the West facing array. This is yesterday’s output: I haven’t yet mapped it onto the available data but the chances of that being a true reflection of what the sun was doing is nil. I’ll get onto the installation company for the issue to be investigated. Link to comment Share on other sites More sharing options...
G and J Posted December 7 Share Posted December 7 42 minutes ago, Omnibuswoman said: You guys!! Honestly, I’ll never get the house finished if I let myself get distracted with this kind of thing, which is right up my street… I will add it to next year’s Christmas present list, IF I’ve finished the house… Meanwhile, there’s clearly a problem of some kind with the West facing array. This is yesterday’s output: I haven’t yet mapped it onto the available data but the chances of that being a true reflection of what the sun was doing is nil. I’ll get onto the installation company for the issue to be investigated. It does seem to suggest an intermittent issue with the west solar wiring. Have you an app for the inverter? If you do can you see input voltages? Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 19 minutes ago, G and J said: Have you an app for the inverter? If you do can you see input voltages? I do have an app - Solis app. I’m not sure how to view input voltages. I’ll find out! Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 It looks as though the information I have access to via the app is limited, unfortunately. I can’t interrogate the inverter activity other than with respect to the four main parameters, and in watts or kilowatts only. Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 This is all I can find. No live data for voltage. Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted December 7 Share Posted December 7 3 minutes ago, Omnibuswoman said: This is all I can find. No live data for voltage. the live data will be available on the front of the inverter, using the display, assuming that all Solis inverters do it this way, certainly how my AC coupled storage inverter does it Link to comment Share on other sites More sharing options...
G and J Posted December 7 Share Posted December 7 Is that right now? If so it appears to be showing both sides doing a bit as you’d expect this close to noon, if your ridge is more or less running due north to south. Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 10 minutes ago, G and J said: Is that right now? If so it appears to be showing both sides doing a bit as you’d expect this close to noon, if your ridge is more or less running due north to south. I think you’re right, it is live data. The numbers change when I refresh the app. What I can’t do is look backwards. I will take screenshots of the live data this afternoon at intervals, and will post up here later on. Link to comment Share on other sites More sharing options...
G and J Posted December 7 Share Posted December 7 I’d be watching for a gradual change in voltages between the two dc feeds as the sun goes round. Ok today may be a bit hopeless but still, if you catch it with zero on one feed screenshot it, it’s hard data that will be useful for diagnostics. 1 Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 Caught it! See series of images below… 1 Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 So these show voltage but no current… I’m not sure how to interpret the voltage data. I assume that PV1 is East and PV2 West, but only because I would expect East to be higher in the morning. @SteamyTea - any thoughts? I don’t know enough about power to know what might explain this… Link to comment Share on other sites More sharing options...
SteamyTea Posted December 7 Share Posted December 7 25 minutes ago, Omnibuswoman said: any thoughts Your export voltage is limited to 253V, so if it goes above this, it can shuts the inverter down, or through electronic magic limit the export. I could be that. If it is, the only thing you can do is have a word with the DNO and see if they can adjust the local transformer. They don't usually like doing that. Link to comment Share on other sites More sharing options...
JohnMo Posted December 7 Share Posted December 7 10 minutes ago, SteamyTea said: export voltage is limited to 253V How far is the inverter from the consumer unit? If a long distance you could have a big enough voltage drop, that the inverter is producing enough volts that it goes off because it's hitting max voltage point for trip. Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 Thanks both. @SteamyTea that theory correlates with the power stopping when the voltage surpasses 250v, however we exported electricity all summer with no obvious issues and I would have expected that to have done the same. However I only have octopus export data for that so I can’t know what exactly the panels were doing then… @JohnMo I have two consumer units - one next to the inverter, in the workshop, and a second one in the house, maybe 15 metres away, where a very large 5 core cable comes in from the workshop. You can see the cable exiting the workshop consumer unit in the below photo. Link to comment Share on other sites More sharing options...
SteamyTea Posted December 7 Share Posted December 7 8 minutes ago, Omnibuswoman said: however we exported electricity all summer with no obvious issues and I would have expected that to have done the same. All depends who else is, or isn't, pumping some power in. This was a fairly common occurrence in the initial solar boom. Too many people had PV fitted and the local voltage rose too high, leading to a lot of upset customers. This is why the default is 16A per phase, but even then it can give local problems. It is part of the reason that older 'council housing' has not been retrofitted with PV, even when there was funding for it. No one wanted to pay for the grid reinforcement. I was involved with PV installs back in 2010, we did 4 installations, all 4 kW, 16A, and got sent a bill for a new DNO transformers. Apparently there is a clause that allows this. The business owner just dissolved the company. I had left by then as he was a crook and assumed that the rules only applied to others. Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 Hmmm 🤔 That’s quite a worry… looking back at the data I have, I’ve not had a problem of overvoltage related shut down prior to late November. Very few homes here have solar PV - we are only one of two that I am aware of. When Storm Bert passed through on 23rd Nov there was a local powercut (although my home wasn’t affected). I wonder if when restoring the power they changed something in the local supply configuration. I know from the research I did before connecting to the grid that the local supply is on its knees. The DNO were trying to surreptitiously get us to fund a local area upgrade. I will speak to our installer to ask if they’ve heard of any issues with other local people. Link to comment Share on other sites More sharing options...
G and J Posted December 7 Share Posted December 7 Well done for gathering that data. What else does your system include? I don’t know enough about it to recognise the boxes in your pic. Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 @G and J we have a Solis inverter and two 3.6kW Pylontech batteries. Our electricity supply is three phase. We have also had capability to use the inverter off-grid built in, so one of the switches is for us to disconnect from the grid and operate independently. Link to comment Share on other sites More sharing options...
G and J Posted December 7 Share Posted December 7 Hmmm, can you simply isolate the battery systems to see if the behaviour persists? And have you a clamp (he writes as if he understands exactly how they work!) Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 7 Author Share Posted December 7 20 minutes ago, G and J said: Hmmm, can you simply isolate the battery systems to see if the behaviour persists? And have you a clamp (he writes as if he understands exactly how they work!) I could have a look at the instructions and find out if I can do that. I don’t have a clamp, and even if I did I wouldn’t have a clue what to do with it 😂 Link to comment Share on other sites More sharing options...
SteamyTea Posted December 7 Share Posted December 7 11 minutes ago, Omnibuswoman said: look at the instructions RTFM usually helps. As you are 3 phase, I would not have thought that the voltage was going to high, but as you said earlier, your local grid was weak. It may be possible that the battery system is fighting against the PV system, which may be by design i.e. start discharging batteries when they are full (or close to it). Is the PV and batteries on separate inverters? Link to comment Share on other sites More sharing options...
JohnMo Posted December 7 Share Posted December 7 2 hours ago, Omnibuswoman said: have two consumer units - one next to the inverter, in the workshop, and a second one in the house, maybe 15 metres away It would be worth checking the voltage at both CUs they should be about the same. Check them at different times of the day to see the difference. Link to comment Share on other sites More sharing options...
Dillsue Posted December 7 Share Posted December 7 The DNOs max supply voltage is 253vac but your inverter can likely push the house voltage higher before it shuts down. Before our DNO upgraded our transformer mine has in the past run up to 262vac before it shuts down. Link to comment Share on other sites More sharing options...
Dillsue Posted December 7 Share Posted December 7 If you look at the grid voltages in the snap shots you posted, the L3 phase is up to 252.4vac when your only generating a few hundred Watts, so you're running close to the grid max. Maybe your inverters grid voltage limit has reset to 253vac after the power cut and you're hitting that? If you put a load on that phase, like an electric fire, it will pull the voltage down. Maybe add a kw or 2 of load to each phase when you want to test things Link to comment Share on other sites More sharing options...
Omnibuswoman Posted December 8 Author Share Posted December 8 Could one of you signpost me to an idiots guide to basic electrical knowledge pls? I honestly can’t have been listening in my GCSE physics class as I don’t have even the most basic understanding, beyond that multiplying voltage by amps equals power. The problem has clearly worsened the less load I have put on the system - I was aiming for @SteamyTea levels of daytime usage, and that seems to be correlated to the problem. What I don’t understand is why that is… Link to comment Share on other sites More sharing options...
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