The photo and diagrams below show how to wire a junction box to run up to five lights. The boxes shown are 80x80x50mm deep and have eight rubberized grommets through which wires are simply pushed. However, there is practically only room for wiring one inlet and a maximum of five outlets.
Please note that although some exterior transformers can be buried, junction boxes, which are typically rated at between IP44 and IP65, need to be mounted above ground.
The thicker wire at left is the input from the transformer, all others are outputs to lights. Five is the practical maximum from this size of junction box.
1. Wire the input wires from the transformer first. This cable is usually thicker than the other wires, dependant upon transformer wattage. Note there is no earth wire on 12v circuits.
2. We've now added two jump wires to the next bays in the terminal block
3. Up to five light outputs can now be added. Do NOT slit the rubber grommets in the box to allow cable through, rather use something blunt like a small screwdriver - otherwise, the grommet may not seal properly.