14 2 Wire For Led Lights . The first number, 12, indicates the wire diameter while the second number determines the number of wires the cable contains. At the time, di diego was having trouble finding answers to “led wiring 101” questions about wire gauge options, voltage regulation issues, and other quirks of running dc circuits. 300' Red 2Wire LED Rope Light Flexible Home Outdoor Christmas Lighting from www.walmart.com Identify and tag that circuit at the panel and replace the 20amp circuit breaker with a 15 amp, then. To light a few leds (i.e. Take that bell wire and fpl to the diy forum.