Solar Cabling

Solar cable, MC4 leads and array earthing, in 4 mm2 and 6 mm2.

Everything here is made to AS/NZS 5033:2014, the New Zealand solar standard in force since July 2015. It is UV resistant, halogen free, rated 1000/1800V AC/DC and -40°C to +90°C, with a 25 year outdoor design life. Ordinary building electrical cable such as TPS will not do this job. It goes hard and cracks after a few summers on a roof, and it was never rated for the voltage a string of panels puts across it.

There are three ways to buy it. Array leads have an MC4 on one end and bare wire on the other, for the run from the panels to your charge controller. Extension leads have MC4 on both ends and go into a run that already exists to make it longer. Solar cable is sold by the metre with nothing on either end, so you cut it to length and terminate it yourself as needed.

Twin core applies enough cable to do two cores. Usually these are connected together, which is one cable to run and one hole to drill. Single core is two separate cables you route yourself, for when the legs take different paths or there is a combiner on the way. Both sizes come either way.

Size it on voltage drop rather than on heating. A solar run loses you the same slice off every kilowatt hour the array makes, every day, for the life of the system, so it is nearly always cheaper to go up a size than to live with it.

The array frame needs earthing as well. The 4 mm2 earth cable and a 2000 mm copper plated rod with its brass clamp are both here.