Back Einphasen-Dreileiternetz German Sistema de fase partida Spanish برق شکستهفاز Persian 単相3線式 Japanese Enkelfasig driedraadssysteem Dutch Sistema de fase dividida Portuguese
A split-phase or single-phase three-wire system is a type of single-phase electric power distribution. It is the alternating current (AC) equivalent of the original Edison Machine Works three-wire direct-current system. Its primary advantage is that, for a given capacity of a distribution system, it saves conductor material over a single-ended single-phase system.[1]
The system is common in North America for residential and light commercial applications. Two 120 V AC lines are supplied to the premises that are out of phase by 180 degrees with each other (when both measured with respect to the neutral), along with a common neutral. The neutral conductor is connected to ground at the transformer center tap. Circuits for lighting and small appliance power outlets use 120 V circuits connected between one line and neutral. High-demand applications, such as ovens, are often powered using 240 V AC circuits—these are connected between the two 120 V AC lines. These 240 V loads are either hard-wired or use outlets which are deliberately non-interchangeable with 120 V outlets.
Other applications of a split-phase power system are used to reduce the electric shock hazard or to reduce electromagnetic noise.
- ^ Terrell Croft and Wilford Summers (ed), American Electricians' Handbook, Eleventh Edition, McGraw Hill, New York (1987) ISBN 0-07-013932-6, chapter 3, pages 3-10, 3-14 to 3-22.