scotjimland
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- Jul 25, 2007
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I raised this topic on another thread but as it is so important thought it worthy of it's own post..
There is no point in spending ££££ on panels and charge controller then skimping or fitting incorrect (too small) sized cable .. failure to do this and your panels will under perform and disappoint ..
This is so important with a low voltage system.. where you MUST take into account the
* System Voltage
* Max. Current
* Acceptable Volt drop
* Cable length
To illustrate how cable length affects volt drop and the cable size required..
An 80watt panel with two different cable length runs..
Panel voltage = 17V
Max current = 5A (panel watts/voltage)
Acceptable volt drop = 1%
Cable length = 3mt
Cable required = 4mm2
Increase cable length to 6mt and you have to increase cable size to 16mm2
To calculate use this handy cable sizer ... http://www.solar-wind.co.uk/cable-sizing-DC-cables.html
There is no point in spending ££££ on panels and charge controller then skimping or fitting incorrect (too small) sized cable .. failure to do this and your panels will under perform and disappoint ..
This is so important with a low voltage system.. where you MUST take into account the
* System Voltage
* Max. Current
* Acceptable Volt drop
* Cable length
To illustrate how cable length affects volt drop and the cable size required..
An 80watt panel with two different cable length runs..
Panel voltage = 17V
Max current = 5A (panel watts/voltage)
Acceptable volt drop = 1%
Cable length = 3mt
Cable required = 4mm2
Increase cable length to 6mt and you have to increase cable size to 16mm2
To calculate use this handy cable sizer ... http://www.solar-wind.co.uk/cable-sizing-DC-cables.html