6mm Solar Panel Cable - Where from in the North West??

Jonny_H

Jonny_H

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Just installed a new solar panel - after a lot of fighting managed to get the cables run, however having spent several hours routing them through various inaccessable parts of the boat have found them to be 8ft foot short /forums/images/graemlins/frown.gif

The cable that was supplied with the panel is 6mm double insulated tinned low loss cable. I'd like to get the wiring finished whilst in the north west this week, anyone know where to get some more of this cable from?

Also, whats the best way to join the cables to get minimal voltage loss?

Thanks

Jonny
 
Mail order from merlin Powerstore perhaps. They have flat or round upto 5mm²

6mm² sounds pretty heavy are you sure? Very large solar panel?
(in domestic terms 6mm² is what you'd use for cookers and showers)

Joint. Solder with a couple of layers of heat shrink maybe but that'll make a bulky joint in 6mm² A junction box maybe with good size terminals.

Dont forget to fit a fuse at the battery end of the cable.
 
Its an 85 Watt panel - the suppliers said I could use 2.5mm twin core, but they gave me as part of the deal the '6mm solarflex single core tinned copper cable is double indulated and designed for solar and wind installations, it is not cheap but will allow you to get as much power from the panel to the controller' as I have already run this for most of the distance I may as well carry on with it for the rest of the run - not much point having 6mm for the first 9 metres and 2.5mm for the last 2 metres!

I could mailorder it, but am in the north west this week and out and about and thought it may be good to pick it up to avoid post delays etc.

Jonny
 
[ QUOTE ]
solder the joint for sure

[/ QUOTE ] In view of the cable size would you use some sort of joining ferule with the cables soldered into that. A double ended crimp perhaps, also soldered.

Before long someone will say don't solder as the cable will fatigue adjacent to the joint. Crimp with a heavy duty crimping tool.
 
An 85W panel will produce around 5 amps max (85W at 17v or thereabouts). 2.5mm^2 cable is good for up to 20 amps (Index marine catatlogue page 20). For a run of 10m X 2 (20m total) the volts drop is less than 1 volt. Considering that you are going to put a regulator before the battery (??) then you will drop the volts from 17v (or whatever your panel produces) to around 14.5 volts in any case, so the volts drop due to the cable will be unimportant.

Wether you use tinned 2.5mm^2 cable or not is up to you and your wallet; but I would consider 2.5mm^2 more than enough for your installation. Why not keep the cable that you have installed and use 2.5mm 'tails' with a good quality terminal block with screws and crimped ring connectors on the cable ends. I don't see any problem going with 6mm^2 for most of the run and then using 2.5mm^2 for the last bit.

Could you site your regulator where the 6mm ends and then use 2.5mm from the regulator to the battery (with a fuse)??? You will have to have a "break" in the cabling for the regulator in any case, so this method would use the natural break.

Alan.
 
Alan,

Thanks for this. I have a Rutland HRDX controller / regulator already installed for the wind genny which will take the solar input and regulate / split for two battery banks. I don't want to move this if it can be helped.

I see your point re 2.5mm^2 tails on the main cables - I have some tinned 2.5mm^2 twin core cable already left over from another job so could just use that I suppose. I would have thought a jointing ferule with the tails soldered and then crimped using a hand crimp would suffice for this joint (with heat shrink over the top)?

Thanks for all the input so far

Jonny

note to self .... next time double the estimate for any cable ordered no matter how generous you think your measuring has been!!!
 
Jointing ferrule with heat shrink should be fine; I imagine the joint is in a dry part of the boat?

Use the 2.5 cable that you already have and have a beer or three with the money that you have saved!!

Alan.
 
[ QUOTE ]
No need for fuse with hrdx either.

[/ QUOTE ] ????????????????? Any extra equipment added should have a fuse in the line as close as possible to the battery. The purpose is to protect the wiring in the event of a short. The fuse rating can be chosen to suit the wiring size although it need only be a little more than the maximum current that will be expected in in the circuit in service.
 
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