Quickie Solar Question

[BlueStringPudding]

Cheers, Chris

 

As this cable would be carrying 53v would I have to run it in separate conduit to the 12v cabling I have?

[Chris Pink]

no, it's still low voltage DC

[BlueStringPudding]

Marvellous. Thanks.

[smileypete]

It's t'other end I need to resolve. The best site for my panel, for me when boating single handed, is a spot on the roof 16m from the controller. So that's 16m of red and 16m of black cable. If that was 6mm cable, whassat in voltage drop for my panel? It's a 250w panel chucking out around 53v. And how terrible is that voltage drop in the bigger scheme of things!? what am I losing battery end by having that voltage drop panel end?

I get different figures for the power loss than the ones Justme gives

 

For 4.7 amps though 32m cable, for different cable sizes I get:

 

1mm² = 12W lost

1.5mm² = 8W lost

2mm² = 6W lost

2.5mm² = 4.8W lost

4mm² = 3W lost

 

So I'd say go for something between 1.5mm² and 2.5mm² depending on cost, for example

 

http://www.ebay.co.uk/itm/251055879887

 

or if you're a bit brassic:

 

http://www.ebay.co.uk/itm/280721925136

 

If there's some unused speaker cable running down the boat, it may not be chunky enough, maybe strip a bit of plastic off and compare it to 13A mains cable which should be 1.5mm²

 

cheers, Pete.

~smpt~

Edited June 12, 2012 by smileypete

[BlueStringPudding]

Thanks for your advice everyone

[Justme]

Just use the right solar cable.

 

You need the double insulation & UV protection that the right cable has.

 

SmileyPete, The cable calcs I used was not clear if the cable length input required was one way or total distance so that could explain some of the variation.

 

 

Either way it so small a loss just use the standard 4mm2 cable.

[smileypete]

Just use the right solar cable.

 

You need the double insulation & UV protection that the right cable has.

 

Think BSP plans to run it in conduit inside the boat, so buying a full 32m of solar cable isn't really needed.

 

Wonder if the panel hasn't got a long enough lead to reach the cabin entry point, if so a bit of solar cable or something similar wouldn't go amiss.

 

cheers, Pete.

~smpt~

[BlueStringPudding]

It's perfectly positioned over a spaceship, Smiley (roof vent)