Split Phase
Split Phase : A split phase electric distribution system is a 3-wire single-phase distribution system, commonly used in North America for single-family residential and light commercial (up to about 100 kVA) applications. It is the AC equivalent of the former Edison direct current distribution system. Like that system, it has the advantage of saving the weight of conductors for the installation. Since there are two live conductors in the system, it is sometimes incorrectly referred to as "two phase"