Help with string inverter problem

PotentialEnergy

OK folks:
Closer inspection of the Ts&Cs has the following so can you tell me whether I pursue the Installer or SMA? I strongly feel the item as being not of sufficient Quality from a reliability perspective. The 'system installation' has a lower case S for System whereas all the rest are upper case S. The installer is offering installation of the replacement Free Of Charge.
Wrt what aspect does the Sales of Goods and Services Act 1982 differ?

5 Warranty

5.1 We do not manufacture the System equipment or components and can not ourselves warrant or guarantee their performance. The principal equipment within the System each comes with a manufacturer warranty. These warranties cover manufacturing faults, satisfactory quality of the equipment within the meaning of the Supply of Goods and Services Act 1982 and fitness for purpose for which the equipment is designed. If you need to make a claim under the warranty, we will administer this process on you rbehalf and ensure that your claim is dealt with appropriately by the equipment provider.

5.2 We warrant that the System will comply with the Order, as may be amended by paragraph 2.4 [all about quotes and discussion of the system]

5.3 We warrant all other goods and labour that form part of the System against failure or breakdown for a period of 6 years from the date of commissioning.

5.4 The entire system installation is covered by a 6 year insurance backed warranty.

5.5 You must inform us when you become aware of any faults in the System., otherwise you could invalidate your warranty.

Thanks again for any more help!

zeupater

PotentialEnergy wrote: »

OK folks:
Closer inspection of the Ts&Cs has the following so can you tell me whether I pursue the Installer or SMA? I strongly feel the item as being not of sufficient Quality from a reliability perspective. The 'system installation' has a lower case S for System whereas all the rest are upper case S. The installer is offering installation of the replacement Free Of Charge.
Wrt what aspect does the Sales of Goods and Services Act 1982 differ? ....

Hi

In my opinion you're placing a little too much attention to the reasonable life expectancy of goods, particularly the failure of your inverter after just under 6 years of service. The problem with taking this any further will be entirely based on the MTBF and your ability to prove/claim that a 'premature' failure would be due to poor design and/or poor manufacturing components & processes on what will effectively be classified as a consumer electrical/electronic item where MTBF is just that, 'mean time', average etc .... some will fail early, some will fail at 10 years and others will probably still be working perfectly in 20 years time. Any claim/action against the manufacturer would simply be based on a single instance which will be countered by overwhelming statistics proving that the failure rate to date would be well within design life expectations ... with the timescales involved it's simply just not worth pursuing

What you need to consider is that whilst you're prevaricating and worrying about a new inverter or even a £36 cost difference - you simply aren't generating what you should be .... worse than that, given the date of installation you're on the highest FiT rate and are therefore likely losing around/over £25/week which will not be recoverable within the FiT contract - what's gone is gone as the term remains at 25years!.

With the poor generation we've all been experiencing recently, have you thought to check your own generation against other local systems on PVOutput? ... that's the first place I'd start, closely followed by having a look for logged events, generation profiles and history in SunnyExplorer to see if there are any obvious patterns (new source of shade etc) .... but I wouldn't hang around too long or have someone turn up with scaffold and a box full of new cable and optimisers/micro-inverters because it doesn't make sense for anyone other than the installer's turnover ... the holes in my wall and cable positions fit a particular inverter, so I'd just have an electrician check what's there for anything obvious, then replace what I've got on a like for like basis PDQ ...

Anyway, I find it pretty odd that a single MPPT inverter's generation had effectively halved - I'd expect it to work, or not ... so do you have two strings, DC isolators etc ? ... in which case, when the DC voltage was tested, was it done at the inverter, or on the DC cables somewhere ??

Looking at the installer side .... the insurance backed warranty should be backed by third party paperwork, but it looks to effectively cover installation and workmanship only, so things like roof integrity, installation issues etc ...

HTH
Z

Martyn1981

PotentialEnergy wrote: »

Martin
Don't suggest I know the ins and outs but do you risk leaving yourself vulnerable to both systems being out if something goes wrong with this single dualMPPT box? At present if one box goes, your other produces. or does this DualMPPT have built in resilience so it can cope with 2 streams if one part of it goes?

Hiya. Yes you're right, but that's exactly the same case for anyone with two strings going into their inverter now. For many (possibly most) 16 panel systems, they will be running two strings to keep voltage within limits. Anyone with shading issues may have gone for two strings deliberately to quarantine all shading onto one string, and those with split rooves, differing orientations, unbalanced strings (odd number of panels), higher shading etc, will have a dual MPPT inverter already.

So technically, I'm just converting two 1-string inverters, into one 2-string inverter, but having to use 2 MPPT's as the strings are unbalanced.

I'm also intending on getting a 10yr warranty to cover my back, but at this stage it's all theoretical as my inverters might keep going for another 10yrs?


Thinking about what Z has posted, perhaps the question to ask yourself (the reasonable man test) is what life expectancy did you (others) expect when the install took place. I seem to recall thinking 5 to 10yrs, though I fully appreciate that my expectations have gone up since. But at the time ...... is that the 'reasonable' test, I'm not sure?

Also, and again referring to what Z said, I've had a nagging question in my head since your first post about the 'halving' of output. My first thought was that you'd lost a string, perhaps a connector failure etc.

I didn't say anything as I know nothing about electronics, and you said the voltages were ok. If a string has gone down, then your inverter should display both sets of readings (voltage and amperage), do they match? I'm assuming you have two strings, though the SB3800 might just get away with one (I think it has 3) but 16(ish) panels on a single string will probably be too much voltage for the 500V limit.

Mart.

PotentialEnergy

Going on below, I think that for things priced at nearly £1500, that are housed in a garage largely protected from sunlight being in the lee of the house for much of the day; I am surely within my rights to be livid after less than 6 years usage. People across the road had a system installed with 70% of the Wattage and generated 20% more than me on a day in early July. I've taken daily readings for years so I know one of the presumably two strings has gone..

I see a SunnyBoy 3800 at Hollybrook Power Supplies for £1,482.00 Inc. VAT

http:// news.bbc.co.uk/1/hi/magazine/8253915.stm
It works like this. For the first four-five weeks you have a "right of rejection" - if the item you've bought breaks down, you can demand a refund.
For the next six months, you are entitled to replacement or repair of the goods. It is up to the retailer to prove there was nothing wrong with it if they wish to get out of having to do the work. And then after six months, there is still a duty to replace or repair faulty goods, but the onus is on you, the consumer, to prove that there was something wrong.
And the key time span is six years. That's how long goods may be covered by the Sale of Goods Act. It all depends on what "sufficiently durable" means. If a light bulb goes after 13 months, the consumer is not going to be overly gutted. If their washing machine goes after the same time span they are going to be livid.
The government's guidelines say: "Goods are of satisfactory quality if they reach the standard that a reasonable person would regard as satisfactory, taking into account the price and any description."
And be aware that if you go to the washing machine repairer, spend money attempting to diagnose an inherent fault, and find out you have been using it the wrong way, then you are going to be out of pocket.
A key fact is that your relationship in the Sale of Goods Act is with the retailer, not the manufacturer.
"The retailer likes shepherding you off to the manufacturer," says Dr Twigg-Flesner.
And there are still reasons why you might want an extended warranty - they often include loan machines and ongoing technical support that you would otherwise miss out on. But they are not always good value, says Dr Twigg-Flesner

Rest assured I'll be doing something about it very soon and seeking re-course wrt action to recover costs/losses.

zeupater

PotentialEnergy wrote: »

Going on below, I think that for things priced at nearly £1500, that are housed in a garage largely protected from sunlight being in the lee of the house for much of the day; I am surely within my rights to be livid after less than 6 years usage. People across the road had a system installed with 70% of the Wattage and generated 20% more than me on a day in early July. I've taken daily readings for years so I know one of the presumably two strings has gone..

I see a SunnyBoy 3800 at Hollybrook Power Supplies for £1,482.00 Inc. VAT

http:// news.bbc.co.uk/1/hi/magazine/8253915.stm
It works like this. For the first four-five weeks you have a "right of rejection" - if the item you've bought breaks down, you can demand a refund.
For the next six months, you are entitled to replacement or repair of the goods. It is up to the retailer to prove there was nothing wrong with it if they wish to get out of having to do the work. And then after six months, there is still a duty to replace or repair faulty goods, but the onus is on you, the consumer, to prove that there was something wrong.
And the key time span is six years. That's how long goods may be covered by the Sale of Goods Act. It all depends on what "sufficiently durable" means. If a light bulb goes after 13 months, the consumer is not going to be overly gutted. If their washing machine goes after the same time span they are going to be livid.
The government's guidelines say: "Goods are of satisfactory quality if they reach the standard that a reasonable person would regard as satisfactory, taking into account the price and any description."
And be aware that if you go to the washing machine repairer, spend money attempting to diagnose an inherent fault, and find out you have been using it the wrong way, then you are going to be out of pocket.
A key fact is that your relationship in the Sale of Goods Act is with the retailer, not the manufacturer.
"The retailer likes shepherding you off to the manufacturer," says Dr Twigg-Flesner.
And there are still reasons why you might want an extended warranty - they often include loan machines and ongoing technical support that you would otherwise miss out on. But they are not always good value, says Dr Twigg-Flesner

Rest assured I'll be doing something about it very soon and seeking re-course wrt action to recover costs/losses.

Hi

If a car, which costs between 10&20 times as much (or more) fell apart after 6 years you may just about have a point, but we're effectively talking about a consumer product which costs little more than a large screen LED TV did a few years ago therefore the longevity test of a "reasonable person would regard as satisfactory, taking into account the price" would likely be met on price grounds seeing that the unit worked well (?) for almost 6 years.

I believe that the key timespan you mention (6 years) is the upper time limit to make your claim against the retailer, not the manufacturer, which means that you've got a theoretical 2 months to argue about as part of any claim validation/valuation. It is also likely (bordering on certain) that in the event that you're successful, any recompense will account for the years of use of the system, so don't expect anything other than a partial contribution towards a replacement .... but this is purely theoretical as I believe that there's little chance of achieving anything other than increasing your own blood pressure .... I'd simply suggest that you call or visit your local citizens advice office, discuss it with them and see what they say ...

I'm pretty sure that ~£1500 for a SB3800 is pretty steep and probably represents full recommended pricing. I've recently seen SB4000TLs being advertised at somewhere in the £8xxs (+VAT), so your installer should be able to source at around, or well below, that level ...

Regarding the neighbours producing 20% more on 70%Wp system on one 'day in early July' ... if there's a significant difference in orientation that kind of difference could be understandable, so you will need to ensure that the systems face in almost the same direction and are unshaded.

Does your inverter have bluetooth and do you have access to a bluetooth enabled computer ? ... if so, have you downloaded and installed the free SunnyExplorer software and interrogated the performance yet as it may give some clues ...

Regarding 'I've taken daily readings for years so I know one of the presumably two strings has gone' - this really intrigues me. Normally there is an issue with running imbalanced strings on a single MPPT inverter which suggests to me that the string connectivity is to a common DC bus, therefore if the AC output has halved on a single MPPT inverter with two strings I'd be looking for a DC circuit/connectivity issue before anything else, that's why it was mentioned in the earlier post .... if you have two strings you should have two rotary DC isolators and a rotary AC isolator, so the easiest way to check would be to isolate the DC circuits in turn and see if AC generation is the same (depending on test conditions) from each string in isolation ....as always, try to avoid operating the DC isolators under load conditions.

HTH
Z

PotentialEnergy

Hi
Thanks for all your thoughts and contributions.

I actually have legal insurance cover and decided to seek their advice. They felt I was strongly placed so it is a letter to the installers giving them 14 days to respond.
It was the firm's choice of an SMA inverter, not mine, that has led to the problem.
I thought the same as you wrt the time limit, but I was told it is actually 6 years from when the fault is known to have started. Nevertheless, I am going to be quick off the mark.

Wrt a car, how would you feel if you only did 5000miles per annum v doing 25,000 miles per annum and it went Kaput after 6 years? If my equipment was housed in poor quality conditions I'd be more understanding. It is in a garage that doesn't even have a car in it as I don't drive.
BTW - My LED TV was £600 over 10years ago and is still working fine. The Sunny Boy 3800 looks to have been c1200+VAT in 2010.

The neighbour's roof faces exactly the same way and is totally free of shadows as it is a 3 storey townhouse. In fact, I referred them to the firm.

I'm not an electrician/electronics specialist. The firm sent a 3rd party electrician who deemed all the ins and outs were correct so I'm not touching things as it would be asking to invalidate things.

I have an aversion anyway to Bluetooth on the grounds of IT Security. Until such time as I feel secure using it, I shall stay away but there is so little diagnostic info with my model of a Sunny Boy 3800 I'd be surprised if it has Bluetooth. The display rolls between 3 sets of info and that is about it.

I have a good idea of what a day of end-to-end sunshine produces with past years' readings. Late July produces around 22 and my inverter produced about 11 on a day of wall to wall sunshine.

Wrt recompense, it should be borne in mind that I've missed out on FiT payments for several weeks so I can barter with that too; besides being given a bum steer - i.e. the installer denying any responsibility referring to their weasel words saying the system components are outside their scope of responsibility. The solicitor said that they can try all the weasel words they want, but they are responsible for the system under the Sales of Goods Act. After all, they selected SMA, not me, so they can haggle with SMA.

legoman62

I have a Sunny Boy 3800 inverter. You can monitor via bluetooth, using an SMA bluetooth piggy back card.

On my request, the installer fitted the piggy back card.

Took minutes to fit and can be used on the PC with Sunny Explorer.

Lots more info is available with S/E, and if you'd had it, may have helped diagnose your problem.

It also works with the Sunny beam monitor.

My installer also made me aware of the 5 year warranty, with the option to extend.

I have 4 months warranty remaining and have spoken to SMA several times regarding price options.

Good luck with your claim:)

zeupater

PotentialEnergy wrote: »

Hi
Thanks for all your thoughts and contributions.

I actually have legal insurance cover and decided to seek their advice. They felt I was strongly placed so it is a letter to the installers giving them 14 days to respond.
It was the firm's choice of an SMA inverter, not mine, that has led to the problem.
I thought the same as you wrt the time limit, but I was told it is actually 6 years from when the fault is known to have started. Nevertheless, I am going to be quick off the mark.

Wrt a car, how would you feel if you only did 5000miles per annum v doing 25,000 miles per annum and it went Kaput after 6 years? If my equipment was housed in poor quality conditions I'd be more understanding. It is in a garage that doesn't even have a car in it as I don't drive.
BTW - My LED TV was £600 over 10years ago and is still working fine. The Sunny Boy 3800 looks to have been c1200+VAT in 2010.

The neighbour's roof faces exactly the same way and is totally free of shadows as it is a 3 storey townhouse. In fact, I referred them to the firm.

I'm not an electrician/electronics specialist. The firm sent a 3rd party electrician who deemed all the ins and outs were correct so I'm not touching things as it would be asking to invalidate things.

I have an aversion anyway to Bluetooth on the grounds of IT Security. Until such time as I feel secure using it, I shall stay away but there is so little diagnostic info with my model of a Sunny Boy 3800 I'd be surprised if it has Bluetooth. The display rolls between 3 sets of info and that is about it.

I have a good idea of what a day of end-to-end sunshine produces with past years' readings. Late July produces around 22 and my inverter produced about 11.

Wrt recompense, it should be borne in mind that I've missed out on FiT payments for several weeks so I can barter with that too; besides being given a bum steer - i.e. the installer denying any responsibility referring to their weasel words saying the system components are outside their scope of responsibility. The solicitor said that they can try all the weasel words they want, but they are responsible for the system under the Sales of Goods Act. After all, they selected SMA, not me, so they can haggle with SMA.

Hi

When the system was installed you should have been shown all of the components, told what they do and have been given a schematic ... for safety reasons this should have included information on how to isolate the inverter from the panels and the mains if that became necessary. All you would need to do is follow the instructions you were given and switch a couple of switches (normally rotary). As this is pretty standard and falls within normal operating practice, there should be no possibility of invalidation.

Regarding the car, low mileage would potentially make a difference to the 'reasonable' test in some circumstances, but as mentioned earlier, the longevity test would be related to the value and a car is more costly than an inverter or TV. As an aside, if your TV cost £600 10 years ago, then it's likely to be plasma or LCD, not LED, but that's not the issue - it's the value - you can currently buy an inverter for the cost of a TV, what's more, your inverter would have been a similar cost to a TV 6 years ago .... it's a consumer item and consumer items fail, it's just that they don't all fail at the same time, some fail early, some take their time ... of course, that's if the issue is with the inverter, not a string or connectors ...

Regarding the SB3800 ... whether it has bluetooth or not depends on what you bought ... I believe that some were shipped with bluetooth factory installed and there was (/is) the option of an optional field-install board. SMA's bluetooth connectivity employs a proprietary protocol and is therefore pretty secure.

I don't know how far an argument based on the installer's selection of SMA would reasonably go, after-all, they've got one of the best quality reputations in their market sector and, unlike many other manufacturers, have been around long enough to both justify and provide backing evidence regarding this. If you've taken legal advice then that's fine, after-all, a solicitor isn't exactly going to turn away current and/or potential future business, but do make sure that you or your insurance provider is willing to pay for a third party technical evaluation of the failure, whether this is done at your behest or that of the installer, especially so if the root cause is something other than the inverter itself ....

Anyway, it's all up to you ... I've provided all the input I'm willing to provide and still think that there's little chance of receiving anywhere near the level of recompense you would be seeking, if any at all ... you seem to have made your decisions as to the course of action, so I wish you well ... :think: ... particularly in finding another installer ... :silenced:

HTH
Z

Martyn1981

PotentialEnergy wrote: »

I have a good idea of what a day of end-to-end sunshine produces with past years' readings. Late July produces around 22 and my inverter produced about 11.

Hiya PE, sorry to be pedantic, but is the 22 figure best, average, or PVGIS? It jumped out at me because whilst I tend to be at the bottom of the generation tables on here (and Navitron) in kWh/kWp, I do tend to beat all 4kWp systems in sheer generation through the summer months.

22kWh per day works out at 682 per month. But playing with PVGIS I found figures ranging from 470 to 550, from Leeds(ish) to southern coastal. I did find some particularly high figures near Brighton of about 580kWh.

My PVGIS target for July is 20.6 per day, so approx 20 for late July. My actual average is coincidentally 22 (thanks to monster generation in 2013 and 14), so perhaps 21 for late July

Obviously you need to avoid using 'bests' as that's not a fair comparison. My July gen figures vary from 602kWh to 775kWh, quite a range.550kWh is about 18kWh per day. I also keep daily records, and expect around 20kWh at the beginning of July, and 18kWh at the end, so I'd suggest amending that 18kWh average to 19kWh start and 17kWh end.

I hope you don't mind my comments, obviously real results will vary, but if your annual generation (average) is similar to the PVGIS annual figure, then (over time) monthly figures should also be similar.


Regarding checking your inverter as Z suggests, I wouldn't be frightened to do it, and I have no leccy knowledge too. All you are simulating is a brief powercut, so just switch off the A/C isolator, then one of the DC isolators, then switch the A/C back on. Note the voltage, which should give you a clue as to the number of panels operating (you can look the panels up on T'internet to find their voltage figs). Then A/C off, swap D/C's, A/C back on. Then finally A/C off, D/C's all on, A/C on.


Lastly, I don't think you can question the choice of an SMA inverter 5/6 years ago, as they were touted by dare I say it, pretty much everyone, as being the best. No idea if they were/are or not, but if the installers believed it, then that too seems to pass the 'reasonable man' test. For many years quotes posted on here often carried a higher figure for SMA inverters, again suggesting, a higher value was placed on them, though that might not be the case these days (I'm not sure).

Mart.

michaels

Martyn1981 wrote: »

My current inverters are 95% and 91% efficient,

Mart.

Where do you get his data from? Thanks