The wire gauge you use determines the maximum current you can safely pass through the circuit. Too small a wire size will heat up and — in the worst possible scenario — melt, burn a performer, or worse.
The published maximum current rating for the DMX2dim is 15A total. The latest versions are internally thermally protected. When all is working as it should, the device will shut off before a fault becomes catastrophic. This in no way excuses you from using appropriate external fuses for your specific application.
Using NEC (US National Electrical Code) guidelines as a reference point, 16AWG (American Wire Gauge) wire is the largest size you should ever need, and it fits in the screw terminals we provide.
Electrically speaking, the primary concern is resistance of the wire, measured in milliohms. If you keep your wire lengths short, you can get away with much smaller wire than 16AWG. NEC codes presume wire lengths of many feet.)
If you’re a pragmatist, do what I often do: run your application on a test bench with the wire gauge you’d like to use. Run for the full length of time you will be using the device in performance. Ensure the wire, connections, junctions, sockets, etc., do not get too warm to comfortably hold. That’s what matters! If there is little heat, there is little loss, and you’re good to go. If any point has a resistance that is too high, it will become warm, or even hot.
Adjust your design and construction practices to avoid heat. You’ll also get more light out of your lamps and more life out of your batteries.