wiring pv panels

dmpc

Hello....I'm building a house at the moment and am gonna put pv panels on the roof in about a year but want to wire for it now while the electrician is doing first fix...25 meter run from panels to batteries (in the shed) and 20 meter run from batteries back to the main fuse board..any ideas on what type and spec of wire i should use..how many cores and cross section area..
anything i should definately do or not do...thanks.:)

smashey

Moved to Gardening/DIY.

Hoagy

You haven't said what size array you're thinking about, the cable size will depend on that.
Bear in mind that the output is probably going to be 18volts and you can't afford to lose more than 1 volt or your batteries won't charge. To achieve that over 25 metres is going to need large expensive cables.
Any chance of putting the batteries in the attic?

dmpc

I will have to move the batteries to attic if wiring is not feesable.. would rather not have anything in the attic that could start a fire though.. I know the batteries are safe but if i got one bad one,,I don't wanna take the risk.. look at nokia recalling phone batteries because of possible danger... thinking of eventually having 5-6 200 watt panels.

10-10-20

We are talking about apples and oranges here - Li-Ion batteries (in phones and such) have huge energy density and are stablised by controllers built into the casing. Sealed Lead-Acid Batteries are totally different and don't spontaneously explode or catch fire. They are designed to vent safely when faulty and only require basic monitoring and enclosure.

If I was implementing SLAB's, I'd just ensure that they were properly supported and had a base which would collect liquid in the event of loss. Nothing major!

Stoner

As Hoagy said though cutting down the length of the LV run is very important

If you post the specs up here one of us will size the cable for you, it might be a huge cable or it might be workable, we dont have enough info to know that yet, BTW copper is at a record high at the moment.