Solar panel installation

merl said:
When you mentioned 3 runs of Unistrut with one going central I just assumed you'd be fitting them transverse with a bit of overhang each side. Is the Unistrut going lengthways down the van too or are you putting several lengths widthways? If lengthways down the van would you really need more than 2?
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Probably not Merl. Yes Unistrut lengthways down the van so probably 2 would do the job as it's only just over a metre width.
 
Robmac said:
Probably not Merl. Yes Unistrut lengthways down the van so probably 2 would do the job as it's only just over a metre width.
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Having said that though Merl, a 3rd central rail would allow me to fit 6 clamps per panel instead of 4 which may be better, If I do it the same way as @Thistle has done it in post #37.

I'm wondering if 6 clamps would be sufficient for a 20kg panel? Probably I reckon though as there will be further fixings at the front on the wind deflector.
 
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Robmac said:
Having said that though Merl, a 3rd central rail would allow me to fit 6 clamps per panel instead of 4 which may be better, If I do it the same way as @Thistle has done it in post #37.

I'm wondering if 6 clamps would be sufficient for a 20kg panel? Probably I reckon though as there will be further fixings at the front on the wind deflector.
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If you had 2 rails with 3 fixings per side you'd still have 6 fixings per panel AND you'd support each long side centrally to reduce flex as we've already discussed. A 3rd rail down the centre wouldn't be as good I don't think.
Having said that, I've never used unistrut, it looks like you typically have a fixing where the edge of a panel intersects and crosses a rail, obviously this wouldn't happen with a rail running parallel with the edge of a panel but I guess that's something you'd work around somehow.
 
Only ever seen flexi panels on side of motorway ! Unglued. 20kg panel will hold itself to roof so Brackets are to stop it vibratiting and room for wire. Especially if wind deflection is fitted properly.
Mine are 70mm at front and 120mm back on long wheel base roof and 15kg and still up there at 90mph downhill. With No help . Apart for gap between the 2
Just make sure fronts lower so its pushed down
Just to look crazy I think my sky light would come off in a head on at 50mph
 
merl said:
If you had 2 rails with 3 fixings per side you'd still have 6 fixings per panel AND you'd support each long side centrally to reduce flex as we've already discussed. A 3rd rail down the centre wouldn't be as good I don't think.
Having said that, I've never used unistrut, it looks like you typically have a fixing where the edge of a panel intersects and crosses a rail, obviously this wouldn't happen with a rail running parallel with the edge of a panel but I guess that's something you'd work around somehow.
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That's confusing me a little Merl (nothing new!) because the way I understand it is that you can only get 2 fixings per rail? But I've never used Unistrut either.

If you get a chance give me a bell this morning and I might be able to explain what I mean for my set up better over the 'phone.
 
I used fencing brakets with one sode bent 90% and bolted to panel edge, the bottom was the bolted through the roof, as for the wireing it was brought in through a boat deckgland hidden under the panels.
van roof.jpg
 
Robmac said:
That's confusing me a little Merl (nothing new!) because the way I understand it is that you can only get 2 fixings per rail? But I've never used Unistrut either.

If you get a chance give me a bell this morning and I might be able to explain what I mean for my set up better over the 'phone.
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The channel that holds the nut runs full length Rob, you can use as many fixings as you like.
 
merl said:
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The channel that holds the nut runs full length Rob, you can use as many fixings as you like.
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Yes I see that Merl but I don't understand how you could fix the clamps to the side of the panel (as opposed to the ends) as the channel would be under the panel? Again I was only going by post #37 which (to me) infers that you can only have 2 clamps per rail per panel but maybe there are different kinds of clamps?
 
Having used unistrut and cable tray for years in industrial cabling situations it is a 'big boys meccano' kit! We always used the pre galv or st. steel for marine sites, Very versatile with all the fixing options but by no means lightweight, if that could be an issue. If you've not seen it before check it out first before purchasing. We always used 41x41 or 41x21. There are of course other copies of it and probably lighter versions, maybe ally.
Screenshot_20240810_092813_Chrome.jpg
 
Robmac said:
Mine are 1722mm long Neil and 1134mm wide so 382mm longer than yours. Being a PVC as well tapers in quite a lot at the top so the width of useable flat space is quite narrow. If you have a look at the 'Who's awake' thread I have just posted a picture and you will see what I mean.
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Mine are mounted crossways on the van Rob, you said your are going lengthways so will be narrower in width?
 
Uni strut on my van is 25mm deep so low profile. And was fixed at the same time a sky lights. Bolted though roof. mine , pannels tilt both sides for winter power.

20240810_112637.jpg
 
Nabsim said:
Mine are mounted crossways on the van Rob, you said your are going lengthways so will be narrower in width?
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Yes sorry Neil my panels are narrower than yours are long - I get easily confused these days!

But I do have a very narrow flat space on the roof being a PVC and the width only just fits on the flat section.
 
Thistle said:
@Robmac
You are sensible to be concerned, domestic panels are large heavy and imho must be secured using mechanical fixtures.
The simplest method is to use unistrut bolted and bonded to the roof, three lengths minimum to give sufficient support.

The lighter 41x21x1.5mm slotted stuff is more than adequate and provides flexibility for upgrades, tilt mechanisms and other additions e.g satellite dishes at a later date

The panels are attached using conventional solar mounting clamps into M8 unistrut nuts

I have done many installations using Unistrut, e.g. I used 5x3m lengths on the van below because the owners were also adding a deck.



View attachment 133902
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Can I ask where you got your 'Z' clamps from please. The frame on my panels is 30mm.
 
I just went into the wardrobe, the back wall is wet, I can feel the rain leaking in via the panel cable entry thing, I know I sealed it really well so need to find a way to reach up there, a wall or something just for fun the back window has sprung a leak too.


What's next chums?
 
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