<P> 14 / 3 and 12 / 3 cables are also available, used mainly between three - way (two - location) switches, and to have separate wall controls for ceiling fans and their attached light fixtures, or to have one half of a duplex outlet switched and the other always on . </P> <P> 12 / 2 and 14 / 2 can also be used for the rare 240 - volt - only 15 - or 20 - amp plug by clearly marking the white wire red, since there is no neutral wire . Two conductor cable is available with black and red conductors only for this purpose; the outer sheath is likewise red . </P> <P> 277 / 480 - volt cable is identical to 120 / 240, except that neutral is grey and hot is yellow (plus an optional orange, used as the red is). The higher voltage, used only in large non-residential buildings, allows more than twice as much electrical power (in watts) to be drawn through the same gauge of wire . </P> <P> UF - B cable is "underground feeder" cable, which regardless of wire gauge has a solid waterproof grey sheath completely surrounding and filling the space between the conductors, which still have their individual colors . Other types of armored or metallic cable (types AC and MC) have an aluminum casing that may be used as a ground conductor, for which it is not necessary to calculate an equivalent wire gauge . </P>

Which 2 awg conductor has a higher resistance