eversolar 17000tl

[edexlab]

Can anyone help me with finding a pdf of the installation manual for an eversolar 17000tl
I've been on lots of sites and can't seem to find a proper manual just data sheets,
I've been asked to take a look at a 50 kw system which has issues, and had a look for a manual last night gave up in the end hoping that there would be one on site but no luck and customer doesn't think he has a handover pack

Also any thoughts. on these inverters good/ bad or common issues with these?

 

[BruceB]

This one?
http://midsummerwholesale.co.uk/pdfs/Eversolar_TLC10_Manual.pdf

 

[edexlab]

Thanks Bruce thats the one!

 

[Donk]

I've been asked to take a look at a 50 kw system which has issues

What sort of issues?

 

[edexlab]

The building the array is on had an unrelated fire, and the fire service cut the Dc cables, after receiving shocks
someone from the installing firm returned to re string the arrays , but it was an installer and not an electrician so I don't think it was tested again

He decided to change the No of modules per string I'm not sure why it was changed from the original design but the company I'm doing this for say its been run through a design program and its ok

So instead of the original strings I think 2 x 22 and 2 x 13, each inverter is now on 4 strings of 17 , this doesn't appear to be an issue as the inverter is rated for strings max Dc 900v, here there is 2 strings to each input

I have checked the mains side and no issues with the supply, except for lack of an Rcd as its TT, original installing company has been informed and apparently they're sending one.

However the way the strings were wired through the isolators was not correct ,

So I've redone 2 inverters and am returning to do the 3rd tomorrow, this one was not working when I first went there so as yet I don't know what the problem is,

However all the strings had voltages which varied slightly 580 ish volts but were 60v less than the calculated voltage for the strings. 38.2 v x17 modules 649 v (in good sunshine with no shading)

Now I know this figure usually isn't always exactly what you will see when testing but I've never seen it vary by this much before except for the obvious , ie roofer has missed a panel, which if true in this case has happened on every string?????

But again I would only expect to find one modules voltage missing ie 38v rather than 60v
also I'm seeing small stray voltages of upto 10v to earth, so tomorrow I'm going to check voltage , IR etc at the array and test everything again I'm guessing its not going to be an obvious fault here!

 

[SolarCity]

but it was an installer and not an electrician so I don't think it was tested again

I find it puzzling that such a person should actually exist.

I have checked the mains side and no issues with the supply, except for lack of an Rcd as its TT, original installing company has been informed and apparently they're sending one.

And I suppose that is why we get such fundamental mistakes as this.

However the way the strings were wired through the isolators was not correct

And this.

However all the strings had voltages which varied slightly 580 ish volts but were 60v less than the calculated voltage for the strings. 38.2 v x17 modules 649 v (in good sunshine with no shading)

10% less does seem high but perhaps not outrageously off. Are the panels clean?

also I'm seeing small stray voltages of upto 10v to earth, so tomorrow I'm going to check voltage , IR etc at the array and test everything again I'm guessing its not going to be an obvious fault here!

What is the roof covering? Is it bonded? Extraneous?

 

[edexlab]

This job was a one off , faultfinding for the installing company who for reasons unknown couldn't or didn't have someone available to look at this system

"Installer" as in part roof monkey who has also been allowed to play with the wiring , obviously got "electrical" experience as he's plugged in lots of panels,
but not enough to know that wiring positives thru one isolator and negatives thru another makes partial isolation near impossible! and checking string voltages a pain!

Obviously never checked voltage with a meter either

The 3 phase install was done by "qualified electricians" , and I mentioned the the poor standards , got told
"It was subcontractors and you know what that can mean"
I took exception to this as I sub to firms a lot and would jack it in if that was the best I could manage!

Poor job overall by a Company who claims to be experts and market leaders , no cables were feruled and copper strands poking out of the terminals almost touching each other on both AC and DC isolators

Cable tray was 75mm with 24 6mm DC cables spilling over and marks on the cables from the tekscrews they'd used to fix it,

roughly cable tied once every metre, DC cables just slung loose on the roof at the top edge of the array
Cables unsupported at the Db and Dc isolators , labelling of Db in pencil and it was incorrect anyway, the compression glands were loose as were. the Swa glands,

The Standby generator did have a contactor rigged to the Pv system supply, but again not done very well and as I understood it , there should preferably be a time delay in the control circuit , but I may be wrong here (any advice on this would be helpful)

I told the guy from this company and he didn't seem too concerned at all

At the outset I was hoping for potential future work from this company, as things have been quiet lately, but I wouldn't want to be involved with this company if this is the norm!

I've told the customer about some of the things I think need changing here ie departures from regs and suggested he gives the company the chance to put things right

re the array string voltages I did put it down to the panels needing a good clean and got the owner to wash part of the array while I was there and this did improve the readings .

 

[SolarCity]

"Installer" as in part roof monkey who has also been allowed to play with the wiring , obviously got "electrical" experience as he's plugged in lots of panels,
but not enough to know that wiring positives thru one isolator and negatives thru another makes partial isolation near impossible! and checking string voltages a pain!

I've seen some dodgy things on site over the years, but this is absolutely staggering. To get something so obvious so completely wrong makes you wonder what else he could get wrong.

 

[TedM]

If there has been a fire nearby then it is possible that all the panels have a residue from smoke on them. Could easily affect output by 10% and would be almost invisible to the naked eye - depends what material was burning.

 

[edexlab]

This could well be a factor as I don't think they were damaged and replaced , (although it is a dusty environment any way)
but the info was so sketchy about everything even the system arrangement they told me was wrong, so I'm not certain of this it ,
just seemed like they couldn't be bothered and it was a bit of a thorn in their side full stop ,

 

[Gavin A]

However all the strings had voltages which varied slightly 580 ish volts but were 60v less than the calculated voltage for the strings. 38.2 v x17 modules 649 v (in good sunshine with no shading)

Now I know this figure usually isn't always exactly what you will see when testing but I've never seen it vary by this much before except for the obvious , ie roofer has missed a panel, which if true in this case has happened on every string?????

But again I would only expect to find one modules voltage missing ie 38v rather than 60v
also I'm seeing small stray voltages of upto 10v to earth, so tomorrow I'm going to check voltage , IR etc at the array and test everything again I'm guessing its not going to be an obvious fault here!

-0.34%/K Voc temp coefficient is fairly standard, in full sun the panels could well be about 30K above the rated temperature - ie 55 degrees C, so around 10%below the nominal voltage, which on a string of 649V nominal voltage would mean the voltage would be around 65V below the nominal, so there's nothing particularly unusual about that reading, it;s pretty much bang on what it should be.

 

[edexlab]

Thanks Gavin A,
I wouldn't normally worry over this sort of difference as you know there are variables, and you know yourself if you've done it to a good standard , but on this job the poor workmanship and mistakes made me suspicious that it was something the installers had done wrong,
when I get my laptop back i'll post some pics but this'll be next week

 

[edexlab]

 

[edexlab]

 

[edexlab]

Compression glands ?