Under the Choko Tree By Nevin Sweeney

Wiring

All the wiring used is multicore, plastic coated, two run (ie two sets of wires) polarized (ie one wire has white marker along it so I can tell at any point in the circuit which is negative and which is positive), and the thickest wire that I could afford at the time. Originally that was 3.5mm thick (including plastic coating) and obtained from Tandy (who no longer exist), the wire I use now is from Jaycar Electrical and 5.0mm thick. The multicore is more flexible and generally thicker than the single core used for 240 volt house wiring.

The original lighting circuits have up to half a dozen incandescent or fluorescent lights on them and the more lights turned on, the dimmer they get. The newer circuits have only two lights per circuit and with the thicker wire, there is little or no dimming. This is the result of line losses which can be devastating in a low voltage system, so to reduce this to a minimum keep your wire runs as short as possible and your wire as thick as possible, or rather as thick as you can afford!

To connect the wires I originally used the 3M Scotchlok connectors which are designed for use on auto wiring. They usually give a quick, solid connection but can be difficult to get, and over a long time due to build-up of corrosion or whatever they can give a bit of trouble. There are plenty on the wiring in my roof, but these days I tend to use 240v terminal blocks – cheap, accessible, easy to use (although not as quick as the Scotchlok) give a good solid join and they can accept the thicker wires much more easily.

Part of a terminal block

Each circuit has a wired in auto-style fuse on the positive wire so that any short circuits do not result in a fire, and this is critical as one short circuit can burn your house down! So the lesson is – don’t energise any circuit until there is a fuse in line. Initially I used the cylindrical glass automotive fuses, which did the job, but each fuse had to have its own separate mount, which is spring loaded. Over time the little plastic lug that held the spring and fuse in place would harden and eventually snap, so that at the least convenient point in time the lights would go out and I would have go into the garage and play hide and seek with the fuse, (annoying!). The system I use now is based on the European style blade fuses in a fuse block that can take six or eight fuses in a row, the new system also allows me to use the push on type spade terminals to attach the wire, where the other type required soldering (which I never got around to). Overall the new system takes up less space and allows me to number each fuse so that I can record what is on the circuit that each fuse covers. The spade type fuse blocks are available from the El Cheapo style auto accessories places.

Click Here to check out our YouTube Channel