How worried should I be?

[DanB]

I'll take the panel off and get a picture of the wiring later. I don't have a multi-meter, and I don't think I would know enough about this stuff to safely start disconnecting and testing things...

Btw, I didn't leave the shoe - it was connected to my foot at the time

 

[jason121]

Actually I have just made a calculation and both arrays must be producing something, If you turn of one isolator then check voltage output on inverter you will see the change.

As Gavin A said in an earlier post it is possible that it is set up with one MPPT (channel) when it requires two for max efficiency or to perform properly. The front panel will have to come off and the wiring checked (there will be a bridge wire that need removing)

Page 13 shows the bridge wire

http://www.power-one.com/sites/powe...ion_manual_for_aurora_string_pv_inverters.pdf

Look on the floor, you might find the bridge wires, unless there is more.

 

[Orffyreus]

Well spotted Jason121, I was too busy looking at the shoe, it will be interesting to see the inverter with the panel off, maybe a couple of nails acting as a bridge perhaps?

 

[Gavin A]

well the problem is obvious from that video.

they've either run it all into input 2, or one string isn't connected properly, as input 1 is showing no voltage, and no power.

er as someone's already pointed out.

 

[DanB]

Okay, here is the panel:





No shoes this time

There's an 'input' dip switch which is at 'Ind' - is that correct? Going off to look at the manual now.

 

[moggy1968]

unfortunately the manuel is far from well translated!

It takes a bit of working out. I haven't used one of these inverters since SMA bought out the 3600TL so without a manual can't remember how it goes, but as above, they do need to be set up correctly for 2 string operation. It's not just plug in and away you go! If they did look in the manual it's entirely possible they didn't understand it, I had to 'phone a friend' for clarification the first time I did one of these!

 

[Orffyreus]

That all looks ok Dan, apart from the shiny metal cover that should be screwed over the AC connector.

Hopefully you are going to say that you did that and your chimp, sorry electrician did not leave it like that?????

Better get your shoes fitted with rubber soles till all his work has been checked :mickey:

Looks like you need a multimeter or a sparky.

One thing I have come across is that the Jetion panels have a VMP of 51v and a Voc of around 61v. With ten panels connected to the one string that would exceed the max input voltage of 530v for that inverter.

As Pin 2 is showing 399v for six panels I have to wonder if Pin 1 has blown something?

You really need to get a friendly knowledgeable solar guy in your are to have a look in my opinion

 

[Gavin A]

where did we find out that they were using Jetion panels?

399V for 6 Jetion's seems very high for operating voltage, I'd expect that for 8 panels.

if they have run 10 panels in one string then that's definitely going to be why it's not working - hopefully it's not done too much damage.

the other string voltage makes it look like they've run it in 2 strings of 8 though. The other likely reason that a string won't work is that it's been wired in reverse polarity... but if it is the 50V panels, then the issue here is that they'd have to be run as a string of 6 + 2 x 5 panels in parallel to get the voltage in range, which could well involve going back on the roof to rewire it.

this really isn't good enough for a professional installation, it's the sort of thing I'd expect from a DIY install.

 

[Orffyreus]

I had a look at Dans system on PVOutput He has 16 x Jetion 250w panels There is a link on his comment, page 6.

You could be right RE 399v = 8 panels Gavin A but even then, given panel orientation the installer should have known better :behead:

Definitely looks like someone is going to have to go on the roof

 

[Jimy]

How worried should I be?


?

Very worried. That is a disgrace.

 

[DanB]

They are Jetion panels. I think they are JT250SBa

There are 6 panels on the garage roof (so we are assuming that's one 'string'?) and 10 on the house roof.

 

[DanB]

Now I think back, originally they specified the system with two inverters - one for each set of panels, and said they'd do that for the same price. Then when the installers arrived, they said that wouldn't be necessary, and only fitted one. Is this now suspicious too?!

Just trying to work out if this is a good company which has been nobbled by an incompetent sparky, or whether the whole organisation is just bent?

 

[DanB]

That all looks ok Dan, apart from the shiny metal cover that should be screwed over the AC connector.

Hopefully you are going to say that you did that and your chimp, sorry electrician did not leave it like that?????

Read more: http://www.electriciansforums.net/p...710-how-worried-should-i-8.html#ixzz2JaY65GUL

Surely you know by now that I won't have been touching any 'metal covers'?

Having said that, I did put the network cable in, but the voltages involved there are much lower!

 

[jason121]

Based on the information provided, panels will have to come off and be rewired. Two strings wont work on that inverter with that panel.

 

[Earthstore]

Dan, I will just try to explain a couple of things that may help you understand.
If you have 2 sets of panels on different orientations you either need two inverters, or what can be more efficient is one inverter with dual MPPT, basically two inputs, one for one set of panels and one for the other set.

However, the sets of panels need to be wired up correctly, if the panels from different orientations are wired together then the ones that are not in the sunshine will drag the others down, also the voltage of the sets of panels must be within the inverters range, too low and the inverter will not start up, too high and it will either shut down or damage the inverter.
Also the inverter needs to be set up correctly for duel MPPT.

It appears that yours has not been wired up correctly, I can also see a couple of other mistakes too.

My advice would be to pay a local installer to come and write a basic report on this, nothing complicated, and then have a pop at the installation company, at least you would have some hard facts as to what is wrong, alternatively, just pay someone to put it right.
Be warned though that you may need scaffold so it may not be cheap.

If you ask, somebody from this forum may oblige, there are some good chaps on here.

I hope this helps.

PS. Do not play with this yourself, high voltage DC is very dangerous, much worse than 240V AC...

 

[Orffyreus]

Now I think back, originally they specified the system with two inverters - one for each set of panels, and said they'd do that for the same price. Then when the installers arrived, they said that wouldn't be necessary, and only fitted one. Is this now suspicious too?!

Just trying to work out if this is a good company which has been nobbled by an incompetent sparky, or whether the whole organisation is just bent?

It may well be that the company was good but some sparky thought he would be able to walk away with an inverter for free although the lack of response from said company would make me think they were not up to much.

My mistake Dan, I realise that you are wary of touching "metal objects" is this a form of OCD?

RE network cable, I would take it out, and using the spare gland that is in your first pic, refit it through the empty hole next to the AC cable :wink_smile:

I think the general consensus here is that the wiring of the panels needs looking at. Did the installer not leave you a wiring diagram?

 

[Orffyreus]

One consolation Dan is that January has been a bad month anyway so you won't have lost too much...yet!

Solar generation for January 2013. http://www.renewable-energy-resource.net/solardata.html

 

[DanB]

This is the Aurora Communicator today:



I presume both inputs should be showing something?

 

[Orffyreus]

Hi Dan,

Yes they should, as I said before my first step would be to use a multimeter to check if string one was actually generating any power, this way you can rule out any inverter issues.

Then it would be a case of checking how the system IS connected and if thats ok check each panel individually.

Check the DC wiring to confirm that pin 1 is the house and pin 2 the garage.

 

[Gavin A]

all of which should really be done by the installer, although from the pics and this thread, it's a bit questionable whether they actually class as being competent people.

If you do test the DC yourself, then make sure you switch the inverter off first, and be careful about the size of the spark you can get when testing the DC - it could well be running at 600V if it's all in one string, and the flash when pulling your probe away could be surprisingly big particularly if you do it in full sunlight. Remember those cables are live all the time in daylight.

 

[DanB]

Gavin,

There's no way I'm doing anything that involves a spark, or really testing anything myself. I don't know enough about what I'm doing, and also I don't want to give the company any get-out that I could have caused any of the problems by fiddling.

I wrote another even more firmly-worded letter at the weekend to the company to insist that they address this problem or I would take things further. I suggested I would get an independent in, and also report them to TS, NAPIT and REA... That seemed to do the trick, as I got a phone call this morning and they are coming to investigate on Saturday. It's difficult to know whether I trust them to address everything, but I feel obliged to give them a shot, and now I know a lot more about the whole PV game (mainly thanks to everyone here!) I think I should be able to determine whether they are honestly able to fix things.

 

[Vegelen]

It's difficult to know whether I trust them to address everything, but I feel obliged to give them a shot, and now I know a lot more about the whole PV game (mainly thanks to everyone here!) I think I should be able to determine whether they are honestly able to fix things.

Dan, An employee of this company left a dangerous installation at your house and signed it off.
It was left in a state that would worry any qualified spark or individual.
In normal circumstances it is better to give companies the benefit of the doubt to correct their mistakes, in preference to going in all guns blazing, but in this instance this installation was left in a negligent state.
Whoever left it has a mind that isnt working properly or they dont care about how they left it.
Such an individual is a liability to this industry.
Such individuals will cause harm to other people unless stopped.
You are being extremely nice, but your kindness is a threat to other peoples health.
You need to wake up and realise the implications to other people beyond yourself.
You can follow the path of least resistance and let this company correct a very poor installation and let the installer get away with his shoddy work, but he / she will be passed onto someone else.
The more individuals with this mentallity are allowed to get away with it the more they will do it. You need to stop being nice and "wake up".
Get an independent inspector to assess this work. Get a report made. Tell the authorities to inspect it. Let the company deal with the fallout from it.
If your property had burnt down or someone had got seriously hurt, your mentallity would be different.

 

[FB.]

....they are coming to investigate on Saturday. It's difficult to know whether I trust them to address everything.....

If I'm free at the time they're coming, I can drop in to ask difficult questions where necessary; you can remain on speaking terms with them and let me ruffle their feathers with difficult questions if any need to be asked.

 

[FB.]

.....It's difficult to know whether I trust them to address everything......

After they've finished, if everything looks right, and if the array(s) functions within expected ranges relative to other nearby arrays (such as mine), then it's likely to have been addressed.

I can stand beside my inverter and chat over the phone to let you know how much I'm outputting and you can extrapolate that to approximate for your array, based on the number of panels and a slight variation in azimuth.

 

[Orffyreus]

They are not exactly rushing round to sort it out but see what they have to say, probably be best to get things in writing too.

It will be interesting to see what the actual situation is with the panels/setup please let us know how you get on Dan, best of luck.

 

[Joeacox]

I would be defiantly concerned. Especially the exposed wire.

 

[Orffyreus]

I see from your output that they have been and solved the issue with performance Dan. Hopefully all the other issues were rectified too.

 

[DanB]

FB -thanks for the offer. I nearly called on you because I thought I wasn't going to be here this morning, and my wife was going to have to deal with everything, but my plans changed at the last minute!

Was a bit surprised when the same electrician turned up today to fix the problems... He looked a little sheepish, but went with the 'I heard you're having a few problems' line when he arrived. I explained all the concerns, and he said he was sure it was no problem and he could fix them. He went into the loft to look at the inverter, and took about ten minutes before coming down again and saying there had been 'connector in the inverter which should have been connected in the factory but hadn't', which had meant the first string hadn't been working. He was at least prepared to accept that it wasn't the easiest to check and commission the panels originally (ie. when it was DARK!).

He then took the import meter and tails apart, and replaced the chewed cables. It's no great surprise that the new cables appear to have the grey additional insulation on! I did manage to get a quick look at the tails he took off, and although it's a rubbish photo, sure enough there was a lot more damage under the sticky tape:



As soon as he'd finished, the output was pretty much transformed - it was a relatively sunny morning, and the panels were putting out 2kw straight away - far in excess of anything we've achieved so far. He said that the garage and two of the panels from the roof are on one string, and the other eight are on the other.

Sadly, later in the morning the serial cable was knocked out of the monitoring PC and I didn't notice, therefore we don't have a full day of data, so I'm hoping for sunshine tomorrow! Once I have a few days in the bank, I can compare with FB and see how we're getting on

On the whole he was pleasant and polite, but wholly unapologetic. He did leave with a 'if you have any other problems then don't hesitate to call the office'! I imagine it's fairly obvious by now that I won't hesitate to do that!

So I think I have a correctly set-up and safe system working now. Thinking on whether to take the advice of some here and report them in any case due to the shoddy workmanship the first time around.

 

[Marvo]

Wow, I haven't been on this thread for a while and I see it's been very active. Great to hear you eventually got some remedy from the installers. If they've addressed all your issues and your performance is what it should be then to be honest I'd just let sleeping dogs lie. Unless you have plenty of time on your hands and you want to jump through countless bureaucratic hoops for probably no gain then reporting them won't achieve much.

 

[Gavin A]

As soon as he'd finished, the output was pretty much transformed - it was a relatively sunny morning, and the panels were putting out 2kw straight away - far in excess of anything we've achieved so far. He said that the garage and two of the panels from the roof are on one string, and the other eight are on the other.

So I think I have a correctly set-up and safe system working now. Thinking on whether to take the advice of some here and report them in any case due to the shoddy workmanship the first time around.

don't you have 10 east facing and 6 south facing panels?

this set up would mean that you'll have one string of 8 panels that's properly optimised, the other string will always under perform as the peak voltage point of the 2 different orientated arrays will be different.

This is not acceptable unless you'd agreed to this in advance.

 

[Gary K]

don't you have 10 east facing and 6 south facing panels?

this set up would mean that you'll have one string of 8 panels that's properly optimised, the other string will always under perform as the peak voltage point of the 2 different orientated arrays will be different.

This is not acceptable unless you'd agreed to this in advance.

I would query how this is going to work effectively. They must be aware that this is not the way to go as you have already stated that you would need two inverters. If you have the original quote in writing, I would suggest that you insist that they honour it.

 

[FB.]

........it was a relatively sunny morning, and the panels were putting out 2kw straight away.....

At the moment, on the bright sunny mornings, my 3.75kWp ESE 40'pitch are peaking around 2.25 kW output and managing just under 10kWh total for the day.

In the dark days of December the peak in direct sun was about 1.75kW. It'll be about April before they reach the full 3.6-3.7kW output. In mid-summer the output will often fail to go above 3kW due to the panels getting hot.

Feel free to message me to ask what kind of peak power readings I'm getting on bright mornings.

A couple of random pictures of my inverter screen are below, to give some ideas of what to expect. The notches on the left axis are 1kW and the top of the chart is 3.6kW
- you may just about be able to see the dates of "24 Apr" and "24 June" ".
The first was a cloudy morning and sunny afternoon - not much use for ESE-facing panels.
The second was a day with a mix of sun and cloud - you can see the steep drops in output as the sun was blocked. You can also see the left-shift of the chart due to the sun position relative to the panels.

 

[FB.]

don't you have 10 east facing and 6 south facing panels?

He does, from what I can see.
But I can't see anywhere on this topic where the string voltages had been ascertained to see whether it was a string of ten and a string of six, or whether it's two strings of eight.
Nor have I seen exactly the Vmp (maximum power voltage) of the panels he has and how that works with his inverter.

 

[Gary K]

FB -thanks for the offer. I nearly called on you because I thought I wasn't going to be here this morning, and my wife was going to have to deal with everything, but my plans changed at the last minute!

Was a bit surprised when the same electrician turned up today to fix the problems... He looked a little sheepish, but went with the 'I heard you're having a few problems' line when he arrived. I explained all the concerns, and he said he was sure it was no problem and he could fix them. He went into the loft to look at the inverter, and took about ten minutes before coming down again and saying there had been 'connector in the inverter which should have been connected in the factory but hadn't', which had meant the first string hadn't been working. He was at least prepared to accept that it wasn't the easiest to check and commission the panels originally (ie. when it was DARK!).

He then took the import meter and tails apart, and replaced the chewed cables. It's no great surprise that the new cables appear to have the grey additional insulation on! I did manage to get a quick look at the tails he took off, and although it's a rubbish photo, sure enough there was a lot more damage under the sticky tape:

View attachment 17141

As soon as he'd finished, the output was pretty much transformed - it was a relatively sunny morning, and the panels were putting out 2kw straight away - far in excess of anything we've achieved so far. He said that the garage and two of the panels from the roof are on one string, and the other eight are on the other.

Sadly, later in the morning the serial cable was knocked out of the monitoring PC and I didn't notice, therefore we don't have a full day of data, so I'm hoping for sunshine tomorrow! Once I have a few days in the bank, I can compare with FB and see how we're getting on

On the whole he was pleasant and polite, but wholly unapologetic. He did leave with a 'if you have any other problems then don't hesitate to call the office'! I imagine it's fairly obvious by now that I won't hesitate to do that!

So I think I have a correctly set-up and safe system working now. Thinking on whether to take the advice of some here and report them in any case due to the shoddy workmanship the first time around.

Yes it has!!!

 

[Gavin A]

He does, from what I can see.
But I can't see anywhere on this topic where the string voltages had been ascertained to see whether it was a string of ten and a string of six, or whether it's two strings of eight.
Nor have I seen exactly the Vmp (maximum power voltage) of the panels he has and how that works with his inverter.

he just stated that this is what the installer / spark just told him they'd done.

also a string of 10 wouldn't work.

ps I suspect he had reverse polarity on the string that wasn't working, which the spark didn't want to own up to.

 

[FB.]

He said that the garage and two of the panels from the roof are on one string, and the other eight are on the other.

Ah, the problem with long threads is that it's easy to miss something.

8+8 is not satisfactory.
A string of panels is only as effective as its worst link.
The two on the roof will be hindered in the mornings by the lack of power flow through those on the garage, while those on the garage will be hindered in the afternoon by the lack of power flow through those on the roof.

Even if it does work, the bypass diodes will have to be active for considerable amounts of time during the day on bright days, in order to allow the power to bypass the "virtually shaded" cells caused by different sun aspects. It may result in premature failure of those diodes.

 

[Earthstore]

So how did the installer complete the install to comply with the regulations if it was dark, he did not return in the morning, so what figures would he put on his test sheet?

 

[Gavin A]

So how did the installer complete the install to comply with the regulations if it was dark, he did not return in the morning, so what figures would he put on his test sheet?

0 Voc
0 Ioc
0 W/m2
polarity check N
?

This is the sort of rubbish that MCS / real should be chasing up rather than dreaming up ever more complex tick box exercises for us to participate in.