Solar Panels - cables loose on roof?

[moggy1968]

is it flex or the actual bracket moving on it's mountings? some brackets do flex a bit (slate ones we use are quite thin)
I would also never mount an inverter on a stud partition. they are very heavy and also the stud wall can act like a soundboard, making the whole thing a lot nosier.

 

[whinmoor]

Thanks for all of your replies - I feel a bit more confident about complaining now!

Yes, you do need to complain asap as the cables will take a while to wear away after years of rubbing on the slates. Sod's Law says the system will fail when your workmanship warranty has just expired and you'll end up having to fork out for repairs yourself.

 

[farmerdave]

Well, the brackets disappear up underneath the slates and are presumably nailed on underneath the lead shrouding which replaces a slate. The nailing-on point is up the roof a bit from where the brackets attach to the rails so the brackets sort of flex up and down, relative to the roof. Sorry, it's a but difficult to explain.

The inverter is attached to a board nailed between the vertical bit of the roof trusses so it's not actually mounted on a stud wall. The stud wall is in front of the inverter with a hatch cut in. Unfortunately the installers didn't bother asking us otherwise we could have had the stud moved - they just set about it with a big hammer!

 

[powervan]

what brackets have they used? i would say that sort of movement isnt good long term! i have seen a slate job where they used the threaded bar type with nut and bolts at end but these are poor for this type of install!! the bracket and fixings used is the main stay of the system if they got this wrong then i fear a few loose cables is last of your worries!!

 

[whinmoor]

Thanks for all of your replies - I feel a bit more confident about complaining now!

Gavin A, I'm a bit concerned about how the panels are fixed to the roof. There's no sarking board (new build, so we know!) so presumably the brackets are just attached to the slate lats. There's a convenient velux at one end of the panels (2 rows of 8 panels) and you can wobble the nearest panel up and down quite a lot (around +/- 1cm with ease) - most of this wobble seems to be because the brackets move up and down relative to the roof, where they disappear into the lead shroud slate-replacement (sorry-not sure of terminology). The first bracket is around 70cm from the edge of the array. Does this sound normal - is this level of movement acceptable or should I be asking for more brackets?

Thanks, Dave

70cm sounds quite a long distance. Do you mean there's no support nearer the end of the rail? How many brackets are on each rail? Can you take any photos of the mounting system as it's hard to visualise from words? Do you know what make of mounting system you have?

 

[moggy1968]

For the mounting systems we use 70cm is far too far. that would explain some of your flex. The demands on the end bracket and rail are too high, especially in an area of high wind. It's tricky because if you've got 80cm joists the last bracket will be beyond the end of the panels, but I think that would be the only option.

 

[farmerdave]

I,ll put a photo or two up shortly - I don't think I can yet as I'm a noob!

 

[whinmoor]

For the mounting systems we use 70cm is far too far. that would explain some of your flex. The demands on the end bracket and rail are too high, especially in an area of high wind. It's tricky because if you've got 80cm joists the last bracket will be beyond the end of the panels, but I think that would be the only option.

My thoughts exactly. I'd prefer to see some pictures to understand better the situation though. I'd also like to know how many brackets have been used and how close to the edge of the roof the array is situated.

 

[moggy1968]

and the spacing of the brackets

 

[Gavin A]

Well, the brackets disappear up underneath the slates and are presumably nailed on underneath the lead shrouding which replaces a slate. The nailing-on point is up the roof a bit from where the brackets attach to the rails so the brackets sort of flex up and down, relative to the roof. Sorry, it's a but difficult to explain.

actually, that sounds like they've used a reasonable mounting method from this aspect. 70cm overhang however would be more than most (virtually all) mounting rails are designed for.

 

[Earthstore]

Farmerdave, a picture tells a thousand words, so if you could post some that would be helpful, also, why not ask one of the good people on here if they are local to you, and for a small fee would be willing to come and have a look at your system and give you an expert opinion, I feel it would be money well spent for you.
There are many on here that only use good practice, and I am certain one would help you.
Sorry but you are too far from me for me to be of any assistance.
I hope this helps.

 

[farmerdave]

Ok, apologies if I'm doing things wrong here: pic 1- bit of stud wall, now sawn out, that the installers set about with a hammer.
Pic 2) view of inverter in hatch - not much room for accessing USB dock under inverter!
Pic 3) Bits of plaster, presumably these got into the inverter when the installers did 1) above?Pic 4) Cables hanging on roof - some brackets also visible.

 

[Gavin A]

I don't install Fronius inverters, but sincerely doubt that they are permitted to be installed on their side like that, as it will mean it won't be able to dispel heat in the way it's designed to.

 

[whinmoor]

I presume they didn't install the inverter on its side? How much ventilation clearance is there around it?

 

[whinmoor]

I guess he didn't rotate the photo, Gavin :teeth_smile: