solar panel fitting

[Grace and Favour]

LOL the number of times I get called eric on this forum.! I should never have made a username which mashed up my name ....L.E.W.I.S with an old dead cat's name...E.R.I.C

 

Sorry Eric.

[matty40s]

Sorry Eric.

That should be RIP Eric....

 

Lewis, just call him Mr Grace and dont add Young.....

[Grace and Favour]

That should be RIP Eric....

 

Lewis, just call him Mr Grace and dont add Young.....

 

:lol:

Edited April 25, 2012 by Grace & Favour

[lewisericeric]

[Ex- Member]

I like the look of those brackets Eric . . . . but did I read the price correctly? - - - £35 per pair? (in aluminium!!)

 

I would think you should be able to get a local fabricator to make them in stainless for that - (if not cheaper!) (and then you could make them a little higher to improve the panels angle of attack

 

Hi Grace

 

They do seem pricey, but they are adjustable with knob and slot and a holed 90 degree base for fixing. I asked my local fabricator to make similar up in Aluminium It's tricky though as bending a decent thickness alloy is awkward and will most likely crack. Forget stainless steel, even thin at 1mm cutting the slot bending and drilling holes for fixing is time consuming and costly around 20 quid each without knob. The cheapest option was Galvanised sheet cut into triangles it will bend easily and can cut the slot quite easily. Just for the galvanised plate with bend he wanted a fiver each, add the slot and holes with all edges finished properly probably another fiver plus then you have to buy the fixing knob, so even in galvanised you're looking at the best part of 13 to 15 quid each. So a pair ready to go in Aluminium at that price isn't too bad really.

 

Also he always gives me a good price as he borrows our forklift a lot, so a general fabricator would probably charge a lot more than that.

Edited April 25, 2012 by Julynian

[lewisericeric]

Quick question guys , going back on topic....(!!!)

 

Should the cables from the solar panels really be as short as possible ? Can current be "lost" on long lengths of cabling???

 

As I have three panels, I'd rather distribute them around the roof in even intervals to keep the boat looking streamlined so would like one at the front, middle and back. Now obviously, with this, the panel at the front of the boat is going to have to have its cable running 40ft+ back to the controller.

 

Any research or info on this that you guys know about without me having to trawl through search engines

[matty40s]

Quick question guys , going back on topic....(!!!)

 

Should the cables from the solar panels really be as short as possible ? Can current be "lost" on long lengths of cabling???

 

As I have three panels, I'd rather distribute them around the roof in even intervals to keep the boat looking streamlined so would like one at the front, middle and back. Now obviously, with this, the panel at the front of the boat is going to have to have its cable running 40ft+ back to the controller.

 

Any research or info on this that you guys know about without me having to trawl through search engines

You really need to limit cable length to reduce voltage drop.

This is the same advice if having a bowthruster battery charged from the rear of the boat.

If you are committed to doing this, invest in thick cabling 6mm or more.

Otherwise, keep them as close to the battery bank as you can.

[lewisericeric]

Cheers Matt although I think someone mentioned before anyway that it's got to be 16mm cable for these 30v/240w panels?? They're not 12v panels, but the ones used on houses/commercial buildings.

 

Do you think using at least 6mm then will stop any voltage drop?

Edited April 25, 2012 by lewisericeric

[Ex- Member]

Cheers Matt although I think someone mentioned before anyway that it's got to be 16mm cable for these 30v/240w panels?? They're not 12v panels, but the ones used on houses/commercial buildings.

 

Do you think using at least 6mm then will stop any voltage drop?

 

Hi Lewis

 

Chris pink I think it was said 4mm sq would be enough for my set up 6 metres away, you might need to go to 6mm sq as you have a couple of hundred watts more than me, and possibly longer distance. I haven't noticed any solar cable thicker than that on general sale anyway. Also the cable that needs to be equated would be from the panel nearest the battery anyway as the cable linking the first 2 panels will not carry as much load as all 3 panels, only when you link the 3rd panel will full available amps be taken to the charge controller. I think Chris also said use 16mm standard cable from charge controller to batteries.

 

You can buy 6mm solar cable with MC4 plugs fitted, they are some on e-bay but from international sellers, I found some U.K sites though that do sell the 6mm with plugs.

 

ETA I will go for the 6mm regardless, it's not that much dearer and if I upgrade I might not have to renew any cables.

 

 

Edited April 25, 2012 by Julynian

[Grace and Favour]

You really need to limit cable length to reduce voltage drop.

This is the same advice if having a bowthruster battery charged from the rear of the boat.

If you are committed to doing this, invest in thick cabling 6mm or more.

Otherwise, keep them as close to the battery bank as you can.

 

Hmm, I understand that the thicker the cable, the less the voltage loss - - -

 

But AFAIK, the MC4 connectors are designed for 4m² cable aren't they? - they may possibly take 6m², or are there jointing connectors that will take a larger supply cable?

 

 

 

 

Edit: Ooops - - crossed with Julian's post!

Edited April 25, 2012 by Grace & Favour

[Ex- Member]

Hmm, I understand that the thicker the cable, the less the voltage loss - - -

 

But AFAIK, the MC4 connectors are designed for 4m² cable aren't they? - they may possibly take 6m², or are there jointing connectors that will take a larger supply cable?

 

 

 

 

Edit: Ooops - - crossed with Julian's post!

 

I found some here http://renytek.co.uk...tors/4557275703

 

Also a couple of other sites that sell the 6mm cable with MC4 connectors fitted one end, made to any length you require. I forgot to add it to my favourites though I'll find it again though, soon

 

They tend to be described as extension leads, so when searching use that term.

 

ETA here also http://www.shop.solar-wind.co.uk/acatalog/mc4_solar_panel_cables.html

 

 

Edited April 25, 2012 by Julynian

[lewisericeric]

The panels arrived yesterday and with the weather being a bit better today, we've had a look at where they would be placed on the boat. With them being large units (they look very space-agey on the boat - cool!) they'll basically be positions in the middle of the boat. There wont be one right at the back or at the very front of the boat due to a lack of space because of vent positioning etc or the sliding hatch door at the back.

 

Therefore, could I suffer from some voltage drop by positioning them lengthways along the centre of the boat even if i use the 6mm cable?????

 

I want to do this as best I can.

 

Also, a bit of advice on the brackets..... Im going to go with these: http://www.alfrescobay.co.uk/auction_details.php?auction_search=1&auction_id=101310&start=10&option=basic_search&basic_search=brackets&keywords_search=brackets&limit=10&item_type=all

 

But the question is....screw them into the roof, and effectively damage the roof by having screw holes in it which could cause leaks in future; or, attach them with say, those super strong magnets some of you were talking about a few weeks ago, and then thread metal wire through the brackets to the handrails where I can safely put screws/bolts in and not worry about the roof starting to leak in a few years time. What would you guys do??

Cheers chappies

[Chris Pink]

What would you guys do??

Cheers chappies

 

I would drill and tap holes into the roof, it's no big deal to make a threaded hole water tight.

 

6mm² should be fine. Any bigger and you will have issues with the connectors that could undo any benefit from a larger conductor.

 

How long is the run? What voltage and max current will you get before the controller?

 

 

3mm aluminium isn't going to last very long in my opinion.

Edited April 26, 2012 by Chris Pink

[lewisericeric]

 

 

 

3mm aluminium isn't going to last very long in my opinion.

 

Thanks Chris, in what way do you mean they won't last long though? Break or????

[Chris Pink]

yes, I think they'll flex laterally and aluminium is quite easy to break through fatigue bending. The same thing in mild steel would take a lot more lateral abuse.

[lewisericeric]

Hmmm interesting. They seem to be the best ones i can find out there and other sellers are selling similar but also aluminum?

[Ex- Member]

Hmmm interesting. They seem to be the best ones i can find out there and other sellers are selling similar but also aluminum?

 

Hi Lewis

 

I mentioned in a previous post that you could get galvanised steel brackets made up, this might be of benefit as you could have them made higher to increase your panel angle. Might be worth seeking out a fabricator to do this, you could also make the brackets bigger generally to cope with the heavier panels. Chris is right about aluminium and there would be a lot of lateral forces going on with a heavier panel. Side to side movement they're ok but backwards and forwards as you can imagine will flex back and forth and would put stress on the 90 degree bend where they fix to the boat, aluminium is quite brittle.

 

Another thing I would do is not fit the bracket directly to the roof metal to metal with some sealer, I would at least buy some 4 to 6mm thick rubber strip as a packer and bond it as well then fix the bracket through the rubber with tapped holes for screws M6 Or even a hard wood block that can easily be formed to the roof, fixed again with curve and have a nice flat surface to fit the bracket too.

 

I wouldn't worry about voltage drop either, I spoke to an electrician only this afternoon who fit's solar panels. I did mention before that the heaviest load would be from panel 3 which should be the last wired in series and closest to the batteries, The distance of panel 1 assuming it's furthest away doesn't really matter as it's only covering the distance to panel 2 and only carrying the load from 1 panel. The same applies to panel 2 when wiring to panel 3, the load from now 2 panels is only being carried to panel 3. Then panel 3 to your charge controller, but panel 3 should be closer or the closest to your batteries or charger.

 

I was also advised to put a DC isolator next to the charge controller between the panels and charge controller. Reason given was if you need to do work on your solar charger like adding another output or input, you can easily isolate the power from the solar panels whilst you do any work on your charger. more of a safety move as people have disconnected the solar leads and had bad electric shocks or shorts from the bared ends of solar cable.

Edited April 26, 2012 by Julynian

[lewisericeric]

Thanks for the tips Julian - would a fabricator be able to also put that screw fitting in though which goes into the side of the solar panels?

[Ex- Member]

Thanks for the tips Julian - would a fabricator be able to also put that screw fitting in though which goes into the side of the solar panels?

 

Shouldn't be a problem for the metal men as I call them, It's easy to do yourself though. You can buy the hand wheel knobs and fittings on line, some here on flea bay

http://www.ebay.co.uk/itm/200567441443?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_1011wt_1154

 

If you're not confident with a drill though, let metal man do the business. Aluminium is easy to drill but easy to mess up as well Also depending on the rigidity of the frame, it might need additional support from a flange. If a fabricator has to make up the brackets for you I wouldn't think it would cost much more than 3 pairs of alloy brackets, might even be less.

 

The buoy turned up today, I think it'll work. Having seen it in reality I'm much more confident it will. Can't do it for 10 days though as off on holiday.

 

[Grace and Favour]

Snippity>>

 

The buoy turned up today, I think it'll work. Having seen it in reality I'm much more confident it will. Can't do it for 10 days though as off on holiday.

 

 

Holiday! Holiday???

 

You can't go off on holiday at an important time like this

 

Good God man, they don't stop transmitting The Archers for things like 'Holidays'!

 

Send someone else in your place - - then you can continue with the essential stuff!

[Ex- Member]

Holiday! Holiday???

 

You can't go off on holiday at an important time like this

 

Good God man, they don't stop transmitting The Archers for things like 'Holidays'!

 

Send someone else in your place - - then you can continue with the essential stuff!

 

 

I'll still be about as the lap top is coming with me Won't be doing anything boaty though

Although I might visit the Falkirk Wheel whilst in Bonny Scotland

[lewisericeric]

How can you tear yourself away Julian?! Or will you be glad of a break from the boat? I think i'm starting to get totally obsessed with all things boat related. One project gets finished and another started straight away. I dont even want holidays now unless they're on the boat!

 

Have a great time and thanks for the tips. Ive just emailed a steel fabricator and sent him pics of those brackets I was going to get. Ive told him I want them around 40cm high and they must be able to have that hand wheel fitted. I hope he's not going to want any more info, or want some detailed drawings - I'm no engineer!

[Ex- Member]

How can you tear yourself away Julian?! Or will you be glad of a break from the boat? I think i'm starting to get totally obsessed with all things boat related. One project gets finished and another started straight away. I dont even want holidays now unless they're on the boat!

 

Have a great time and thanks for the tips. Ive just emailed a steel fabricator and sent him pics of those brackets I was going to get. Ive told him I want them around 40cm high and they must be able to have that hand wheel fitted. I hope he's not going to want any more info, or want some detailed drawings - I'm no engineer!

 

Well the main reason for going is Lynns' daughters wedding, so turning it into a well earned break, although 10 days on the boat would have been preferable

 

If you give him a base width, then 40 cm high central to that will create the triangle. I would make the base length at minimum 1/3 rd of the panel width, this equals out the stresses, I would always go a bit over so a metre wide panel I would have a minimum 35cm base to the bracket. Did you check that you can see to navigate with the 40cm height, you probably did, but worth checking

 

You can get a good idea of the shape of your triangle by scaling it down and drawing in on paper, if your base is much shorter than I've suggested then the apex will be high and thin, this won't help with flexing back & forth, so try to keep the triangle as equilateral as possible. It's always possible to weld insert a strengthener though, still metal man will advise if he has all the info.

 

 

 

[Chris Pink]

How can you tear yourself away Julian?! Or will you be glad of a break from the boat? I think i'm starting to get totally obsessed with all things boat related. One project gets finished and another started straight away. I dont even want holidays now unless they're on the boat!

 

Have a great time and thanks for the tips. Ive just emailed a steel fabricator and sent him pics of those brackets I was going to get. Ive told him I want them around 40cm high and they must be able to have that hand wheel fitted. I hope he's not going to want any more info, or want some detailed drawings - I'm no engineer!

 

I should be in a position to supply these mounts in stainless or mild steel pretty soon. I'm not sure, at this stage whether to offer them in mild steel as well. They would be about 40% cheaper.

 

I'm not sure of the price at the moment but I am determined they won't be more expensive than the aluminium ones.

 

Send me a message.

 

.

Edited April 27, 2012 by Chris Pink

[David Mack]

LOL the number of times I get called eric on this forum.! I should never have made a username which mashed up my name ....L.E.W.I.S with an old dead cat's name...E.R.I.C

 

I sort of assumed your real name was LEE.