Problems with a new solar install

[Gavin A]

GAVIN A ....are you saying that you would ignore the manufacturers instructions and install 2.5mm cable because you did some calculations !!

scroll down the page a little and you'll see a section specifically stating that cable losses should be less than 1%, and a diagram showing the volt drop for different lengths of different CSA cables, which I referenced earlier.

OK so the diagram is for the 3300TL, but as I said, that's more appropriate here anyway as the system isn't going to be outputing significantly more than the panels rated output very often / at all.

Not that we'd be using 2.5mm2, I'm just pointing out that it's not dangerous to do so, and looks to be somewhere in the region of within manufacturers recommendations and below the 1% max volt drop MCS recommend. Certainly too close for me to want to call it so definitely over the internet as being undersized.

 

[whinmoor]

Assuming that the first photo was taken at about 10 or 11am, I'd say that the top right panel would suffer from shading for a period of time every morning. You need to reduce the effect of this by using a twin-tracker.

A 6-4 split on the Samil is far from best practice. It really needs a 5-5 but the shading will really affect output in the morning.

Get them to swap the Samil for a Power One 3.0 as suggested above.

 

[Gavin A]

I've done some more digging and reading of spec sheets and MCS standards - if I have anything wrong, please shout as my speciality is Electronic Engineering, not electrical...



From the spec sheet for the "DC isolator" (here, page 11), the maximum voltage for purely resistive loads is 300V. For mixed loads, it is 250V or 600V for two poles in series.

The panels have a rated load voltge of 54.7V and an OC voltage of 64.9V, giving a total of 273.5V, 324.5V open circuit, if the pannels are connected as two strings of five or 328.2V, 389.4V open circuit, if the pannels are connected up as they said (6+4). From this, two poles in series are required?

It looks to actually be an AC rated isolator to me from the code, which would be a concern and you'd definitely be within your rights to demand that be swapped out. Hard to say if the DC version would be ok with the links removed or not, could be, could not be, I'd want to check with the manufacturers.

From the MCS PV installation guide (here, page 44) the recommended voltage drop is 1%. Using an online calculator, a 15m run of 2.5mm^2 seems to give a voltage drop of about 2% at the peak AC output current of the inverter.

sunny design puts it at 1.13% with an equivalent inverter at 15m, or 0.98% at 13m. So it's borderline at best, but not actually a safety issue.

This loft has plenty of ventiation as appropriate gaps were left when top-up insulation was done.

maybe so, but a small bit extra isn't going to hurt in itself.

It's a common misconception that felt is there primarily to stop rain getting in - it's not, its main purpose is to prevent wind blown snow getting through into the loft, and help prevent the tiles getting sucked off. Water proofing is a secondary function, but really if it gets to the point that the felt has water running down it then you need to be fixing the tiles sharpish anyway or the battens will have rotted and you'll have to strip the lot instead of replacing the one original broken tile.

 

[heliosfa]

Assuming that the first photo was taken at about 10 or 11am, I'd say that the top right panel would suffer from shading for a period of time every morning.

THe first photo was taken at 12:16. Shading at 10:18 in the morning can be seen in new piccy, taken just before installation started. The return calculations were done by the company with no shading.




One of their "maintenance engineers" has been back once to fix the AC cabling issues and was asked to check the rest of the cabling for any other issues. So they have had an opportunity to identify and fix some of the issues. I also had to remind this "maintenance engineer" to isolate parts of the system before he started undoing cables and he had all of the covers off before isolating the main AC - I think this goes some way to justifying not having them back? I would rather not have to deal with a fried contractor in my cupboard under the stairs...


When they did the install, they cut the seals on both the main fuse and the normal meter (both were sealed by the local network operator about 3 weeks ago as they did a meter swap). As I understand, SSE permit the seals to be removed as long as the person doing it is a member of one of the trade bodies, that the person removing the seals contacts SSE before doing so and that temporary seals (issued by SSE) are put in place. Both the meter and the fuse have been left unsealed and the original installer would not contact SSE - he told me to do it.

When I mentioned this to the company's "contracts manager" he just said that they were allowed to cut the seals as they can't work live, but he would contact the DNO to tell them that the seals were cut and needed replacing.

 

[heliosfa]

Doing some more reading (not good, the more I read, the more I dispair...) what should the initial survey have consisted of? What happened with mine seemed to be mainly the sales lady taking photographs and spending more time talking about what the different panels were and how the Sunpoweres were the best.

Should I have seen any of the calculations they were meant to have done? especialy as the roof is hipped and they should be consulting a structural engineer (page 72 of the MCS guide).

 

[MCS Renewables]

Your return on investment figures are based on the SAP calculation which includes shading analysis, orientation and roof pitch.
Yours is the chart covering Zone 3. ( page 98 of the PV guide)

Without this SAP calculation you have been miss sold which is another RECC issue .

To sum up there is more wrong with your project than right, from initial sale to completed installation and you need REAL and NAPIT to audit your entire Project !

 

[heliosfa]

OK, I have done yet-more digging and the cable that they have used, Pesco H05VV-F, is designed as a light-duty, oil-resistant appliance cord that can be used for fixed-appliances. It is not UV resistant and outdoor installation is NOT permitted.

I have also had a call this morning from their accounts department and I think he realises that there are some major issues with this install. More on this later.

 

[Silly Sausage]

This is probably of no help whatsoever...
If this had happened to me, I wouldn't pay them a penny and I'd insist that they come and remove the whole lot.

 

[JulianC]

They cut the seals on both the main fuse and the normal meter

Other issues notwithstanding, why've they cut the seals on the import meter?? From the pics, I see no reason why the original tails from the meter to the consumer unit couldn't be diverted into Henleys and new tails run in from there. You might want them to get this rectified asap, before allegations of meter tampering start emanating from your energy supplier.

 

[heliosfa]

Other issues notwithstanding, why've they cut the seals on the import meter?? From the pics, I see no reason why the original tails from the meter to the consumer unit couldn't be diverted into Henleys and new tails run in from there. You might want them to get this rectified asap, before allegations of meter tampering start emanating from your energy supplier.

Agreed, if the original sparky had taken some time to stop and think before cutting seals, he could have made his life a lot easier and would not have had to cut the seals. It would have also meant that the install would have been more compliant (no 16mm^2 tails) and the second site visit to fix it would not have been needed.

On the flip side, the fact that he didn't think and left the meter area in such an appalling state is what made me dig deeper and find the other issues so I am kind of glad he did something very obviously wrong.

As for accusations of meter tampering, I don't think my energy supplier will say that when I give them the next reading as I am significantly above my predicted usage at the moment due to experimenting with Bitcoin mining...

 

[MCS Renewables]

Hi
Just been told some interesting things about the "project" lot.

You may need to get the serial numbers of your PV modules and phone them through to Sunpower to make sure that they are what they claim to be.

This company is going to be well known to RECC so keep going, ignoring whatever promises they make.

 

[heliosfa]

Hi
Just been told some interesting things about the "project" lot.

You may need to get the serial numbers of your PV modules and phone them through to Sunpower to make sure that they are what they claim to be.

This company is going to be well known to RECC so keep going, ignoring whatever promises they make.

What is the easiest way to get the serial numbers, bearing in mind that the panels are up and I have no documentation regarding them.

I take it that if the modules are not what they appear to be, there could be problems with their eligibility for FiT?

 

[MCS Renewables]

And the top 100 .......in at number 92 ....

Companies Court Winding Up List 28.10.13

 

[Gavin A]

OK, I have done yet-more digging and the cable that they have used, Pesco H05VV-F, is designed as a light-duty, oil-resistant appliance cord that can be used for fixed-appliances. It is not UV resistant and outdoor installation is NOT permitted.

I have also had a call this morning from their accounts department and I think he realises that there are some major issues with this install. More on this later.

I obviously gave them far too much credit then.

 

[SRE]

I see UK Solar Savings are on the list too - those shiny suits must cost fortune!

 

[solarsavings]

I see UK Solar Savings are on the list too - those shiny suits must cost fortune!

Oh, poor Omar what will he do now

 

[heliosfa]

Sorry to bring this up again, but I don't think it was answered and I don't want to be putting anything in my complaints that is completely wrong!

In the inverter installation manual, it states that an "MCB with rated fault current of 30 mA≤Ifn≤300 mA should be installed between inverter and grid."

Does this mean an RCD/RCBO/ To my untrained mind it does as normal breakers don't have a fault current rated in mA...

 

[MCS Renewables]

Page 16 of the installation manual does require 30mA protection.
So you need an RCBO or RCD in this circuit.

Perhaps you you should start listing what is right with your installation !

 

[heliosfa]

Perhaps you you should start listing what is right with your installation !

The brand of the panels? not saying I have the right model as I didn't get a chance to check in that much detail...

 

[heliosfa]

Right, the complaints have been made and the report forwarded to the installer. Lets see what happens next...