Common Wire Sizes for Home Wiring Installation Common Wire Sizes. Along with wire size, you'll need to consider the wire cable length. In long runs of wire, the resistance of the wire acts like a load, using some of the capacity of the wire load. Thus, a wire capable of carrying 200 amps, may only be good for 180 now. In this case, the next larger wire should be used to allow safe distribution of the load.Wire Cable Length · Larger Ampacity · Guide to Electrical Wire Sizes · Circuit Breaker Or Fuse List of Electrical Cable Sizes | Hunker 14-2 cable contains 2 separate wires, each of which are 14 gauge. The gauge lets a person know just how much electricity the wire can conduct. It is important to know the laws and proper safety techniques to use while installing electrical wiring.