Selecting a Transformer:

Add the total lamp wattage your system requires. (Example: Four 12w lamps and two 36w lamps total 120w.) Choose a transformer powerful enough to handle the total wattage and still have some extra capacity. (In this example our 150w transformer would work, but our 300w would allow for adding more fixtures in the future. Be careful not to overload your transformer: the total wattage's of fixtures wired to a transformer should not be more than 90% of rated transformer capacity.

Selecting Cable:

12 gauge cable is standard. However, for cable runs of over 100', we recommend 10 or 8 gauge. Measure distance from the last fixture on a run to the transformer (or the splice in a "T" run) to calculate the amount of cable needed. Add 1' - 2' of cable per fixture to allow for repositioning.